Acute Coronary Syndrome (Myocardial Infarction and Unstable Angina) (Clinical)

Overview

Definitions^[2,12,18]

Myocardial infarction Myocardial infarction MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction ( MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction):

MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction, commonly known as a “ heart attack Heart attack Mi is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction,” is defined as acute myocardial injury and tissue death resulting from ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage.

• Official definition uses clinical and diagnostic findings.
• Defined as the rise and/or fall of cardiac biomarkers (cardiac troponin (cTn) preferred) with ≥ 1 value above the 99th percentile of the upper reference limit Limit A value (e.g., pressure or time) that should not be exceeded and which is specified by the operator to protect the lung Invasive Mechanical Ventilation and ≥ 1 of the following:
  • Ischemic symptoms
  • ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) changes consistent with ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage (new ST-segment‑T-wave changes or new left bundle branch block Left bundle branch block Bundle Branch and Fascicular Blocks ( LBBB LBBB Bundle Branch and Fascicular Blocks))
  • Pathologic Q waves in the ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG)
  • Imaging showing new findings of myocardial tissue loss or regional wall motion abnormality
  • Intracoronary thrombus by angiography Angiography Radiography of blood vessels after injection of a contrast medium. Cardiac Surgery (or by autopsy)

Acute coronary syndrome (ACS):

ACS is a broad term defined by a condition in which myocardial ischemia Myocardial ischemia A disorder of cardiac function caused by insufficient blood flow to the muscle tissue of the heart. The decreased blood flow may be due to narrowing of the coronary arteries (coronary artery disease), to obstruction by a thrombus (coronary thrombosis), or less commonly, to diffuse narrowing of arterioles and other small vessels within the heart. Coronary Heart Disease or infarction is suspected or confirmed; it includes:

• Unstable angina Unstable angina Precordial pain at rest, which may precede a myocardial infarction. Stable and Unstable Angina:
  • Myocardial ischemia Myocardial ischemia A disorder of cardiac function caused by insufficient blood flow to the muscle tissue of the heart. The decreased blood flow may be due to narrowing of the coronary arteries (coronary artery disease), to obstruction by a thrombus (coronary thrombosis), or less commonly, to diffuse narrowing of arterioles and other small vessels within the heart. Coronary Heart Disease without elevated cardiac biomarkers (no myocardial infarction Myocardial infarction MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction); may or may not have ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) changes
  • With the advent of high-sensitivity troponin, unstable angina Unstable angina Precordial pain at rest, which may precede a myocardial infarction. Stable and Unstable Angina is becoming less common (as cases are categorized as NSTEMI, which has troponin elevation). 
• Non-ST-elevation MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction (NSTEMI): myocardial ischemia Myocardial ischemia A disorder of cardiac function caused by insufficient blood flow to the muscle tissue of the heart. The decreased blood flow may be due to narrowing of the coronary arteries (coronary artery disease), to obstruction by a thrombus (coronary thrombosis), or less commonly, to diffuse narrowing of arterioles and other small vessels within the heart. Coronary Heart Disease associated with elevated cardiac biomarkers and ST–T-wave abnormalities (which include ST depressions and/or T-wave inversions)
• ST-elevation MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction (STEMI): myocardial ischemia Myocardial ischemia A disorder of cardiac function caused by insufficient blood flow to the muscle tissue of the heart. The decreased blood flow may be due to narrowing of the coronary arteries (coronary artery disease), to obstruction by a thrombus (coronary thrombosis), or less commonly, to diffuse narrowing of arterioles and other small vessels within the heart. Coronary Heart Disease associated with elevated cardiac biomarkers and ST-segment elevation in at least 2 contiguous leads

Epidemiology^[10,12,24]

• One of the leading causes of death in the United States
• Prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency: 3% in Americans > 20 years of age
• Incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency in the United States:
  • 600 cases per 100,000 people
  • 1.5 million cases annually
• More common in older patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship:
  • Approximately 60%–65% of MIs occur in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship > 65 years of age.
  • Approximately 33% of MIs occur in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship > 75 years of age.
  • 80% of all MI-related deaths occur in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship > 65 years of age.
• Men > women

Risk factors^[6,7,10]

The risks of MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction increase proportionately with increases in risk factors for coronary atherosclerosis Atherosclerosis Atherosclerosis is a common form of arterial disease in which lipid deposition forms a plaque in the blood vessel walls. Atherosclerosis is an incurable disease, for which there are clearly defined risk factors that often can be reduced through a change in lifestyle and behavior of the patient. Atherosclerosis (also known as coronary artery Coronary Artery Truncus Arteriosus disease (CAD)).

• Nonmodifiable:
  • Older age ( prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency increases after age 35 years) increases risk, with elderly patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship more likely to:
    • Have STEMI than NSTEMI 
    • Have a silent or unrecognized MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction
    • Present with atypical symptoms (e.g., weakness, confusion, syncope Syncope Syncope is a short-term loss of consciousness and loss of postural stability followed by spontaneous return of consciousness to the previous neurologic baseline without the need for resuscitation. The condition is caused by transient interruption of cerebral blood flow that may be benign or related to a underlying life-threatening condition. Syncope)
    • Have higher in-hospital mortality Mortality All deaths reported in a given population. Measures of Health Status
    • Have heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction. Total Anomalous Pulmonary Venous Return (TAPVR) associated with an MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction
  • Gender Gender Gender Dysphoria: men at higher risk than women
  • Ethnicity: Blacks, Hispanics, and Southeast Asians at increased risk
  • Family history Family History Adult Health Maintenance: positive family history Family History Adult Health Maintenance of CAD ( premature Premature Childbirth before 37 weeks of pregnancy (259 days from the first day of the mother’s last menstrual period, or 245 days after fertilization). Necrotizing Enterocolitis CAD) → ↑ CAD mortality Mortality All deaths reported in a given population. Measures of Health Status risk:
    • A 1st-degree male relative < 45 years of age
    • A 1st-degree female relative < 55 years of age
• Modifiable:
  • Smoking Smoking Willful or deliberate act of inhaling and exhaling smoke from burning substances or agents held by hand. Interstitial Lung Diseases
  • Diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus
  • Hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension
  • Hyperlipidemia
  • Obesity Obesity Obesity is a condition associated with excess body weight, specifically with the deposition of excessive adipose tissue. Obesity is considered a global epidemic. Major influences come from the western diet and sedentary lifestyles, but the exact mechanisms likely include a mixture of genetic and environmental factors. Obesity
  • Poor diet (e.g., trans fat, sweets, high processed meat consumption)
  • Sedentary lifestyle

Classification^[1,2,18]

Classification of MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction according to the assumed cause:

• Type 1 Type 1 Spinal Muscular Atrophy: acute thrombus on a ruptured atherosclerotic plaque Plaque Primary Skin Lesions
• Type 2: ↑ oxygen demand in the myocardium Myocardium The muscle tissue of the heart. It is composed of striated, involuntary muscle cells connected to form the contractile pump to generate blood flow. Heart: Anatomy without adequate oxygen supply (whether or not there is underlying atherosclerotic CAD)
• Type 3 Type 3 Spinal Muscular Atrophy: clinical symptoms of MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction with ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) changes, but with death of the patient occurring before lab tests are performed
• Type 4a: MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction associated with percutaneous coronary intervention Percutaneous coronary intervention A family of percutaneous techniques that are used to manage coronary occlusion, including standard balloon angioplasty (percutaneous transluminal coronary angioplasty), the placement of intracoronary stents, and atheroablative technologies (e.g., atherectomy; endarterectomy; thrombectomy; percutaneous transluminal laser angioplasty). Ptca was the dominant form of pci, before the widespread use of stenting. Cardiac Surgery (PCI) or from procedure-related complications associated with ↓ coronary blood flow Blood flow Blood flow refers to the movement of a certain volume of blood through the vasculature over a given unit of time (e.g., mL per minute). Vascular Resistance, Flow, and Mean Arterial Pressure.
• Type 4b: intervention-related MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction with stent/scaffold thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus
• Type 5: MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction related to coronary artery Coronary Artery Truncus Arteriosus bypass graft Graft A piece of living tissue that is surgically transplanted Organ Transplantation ( CABG CABG Surgical therapy of ischemic coronary artery disease achieved by grafting a section of saphenous vein, internal mammary artery, or other substitute between the aorta and the obstructed coronary artery distal to the obstructive lesion. Cardiac Surgery) surgery

Classification of MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction based on ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) findings and pathology:

• STEMI:
  • Due to a major occlusion of a coronary artery Coronary Artery Truncus Arteriosus, causing transmural infarction (through the heart muscle wall)
  • Produces ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) changes with ST elevation and Q waves
• NSTEMI:
  • Due to less severe occlusion of a coronary artery Coronary Artery Truncus Arteriosus, causing a subendocardial MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction (not through the entire heart muscle wall)
  • ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) does not show ST elevation

Pathophysiology

• Characteristics of unstable versus stable plaque Plaque Primary Skin Lesions:^[7]
  • Unstable plaque Plaque Primary Skin Lesions:
    • Thin fibrous Fibrous Fibrocystic Change cap
    • Massive inflammatory cell infiltrate
    • ↑ Activity of metalloproteinase enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body’s constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes (weakens the fibrous Fibrous Fibrocystic Change cap)
    • ↑ Lipid content
    • Angiogenesis Angiogenesis Bartonella
    • Rupture of unstable plaque Plaque Primary Skin Lesions in a coronary artery Coronary Artery Truncus Arteriosus → thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus
  • Stable plaque Plaque Primary Skin Lesions:
    • Thick fibrous Fibrous Fibrocystic Change cap
    • Narrowing of an artery → inability to meet oxygen demand with ↑ exertion 
    • May lead to stable angina Stable angina Persistent and reproducible chest discomfort usually precipitated by a physical exertion that dissipates upon cessation of such an activity. The symptoms are manifestations of myocardial ischemia. Stable and Unstable Angina (symptoms only with exertion)
• Thrombus develops on an atherosclerotic plaque Plaque Primary Skin Lesions, causing ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage (decreased blood flow Blood flow Blood flow refers to the movement of a certain volume of blood through the vasculature over a given unit of time (e.g., mL per minute). Vascular Resistance, Flow, and Mean Arterial Pressure) but no tissue infarction → unstable angina Unstable angina Precordial pain at rest, which may precede a myocardial infarction. Stable and Unstable Angina^[20]
  • In the atherosclerotic plaque Plaque Primary Skin Lesions, there are increasing numbers of lipid-laden macrophages Macrophages The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood monocytes. Main types are peritoneal macrophages; alveolar macrophages; histiocytes; kupffer cells of the liver; and osteoclasts. They may further differentiate within chronic inflammatory lesions to epithelioid cells or may fuse to form foreign body giant cells or langhans giant cells. Innate Immunity: Phagocytes and Antigen Presentation and foam cells Foam cells Lipid-laden macrophages originating from monocytes or from smooth muscle cells. Atherosclerosis.
  • ↑ Plaque Plaque Primary Skin Lesions growth → ↑ elastases and proteases Proteases Proteins and Peptides that cause thinning of the fibrous Fibrous Fibrocystic Change cap → plaque Plaque Primary Skin Lesions fissuring or rupture
  • Exposed subendothelial Subendothelial Membranoproliferative Glomerulonephritis components trigger Trigger The type of signal that initiates the inspiratory phase by the ventilator Invasive Mechanical Ventilation platelet activation Platelet activation A series of progressive, overlapping events, triggered by exposure of the platelets to subendothelial tissue. These events include shape change, adhesiveness, aggregation, and release reactions. When carried through to completion, these events lead to the formation of a stable hemostatic plug. Hemostasis and aggregation Aggregation The attachment of platelets to one another. This clumping together can be induced by a number of agents (e.g., thrombin; collagen) and is part of the mechanism leading to the formation of a thrombus. Coagulation Studies, and platelet products promote vasoconstriction Vasoconstriction The physiological narrowing of blood vessels by contraction of the vascular smooth muscle. Vascular Resistance, Flow, and Mean Arterial Pressure and thrombus formation.
  • Nonocclusive thrombus → unstable angina Unstable angina Precordial pain at rest, which may precede a myocardial infarction. Stable and Unstable Angina ( ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage occurs even at rest)
• Coronary artery Coronary Artery Truncus Arteriosus occlusion → ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage → death of the tissue (infarction) in the area of the heart supplied by that artery:
  • Partial occlusion of the coronary artery Coronary Artery Truncus Arteriosus → affects the inner myocardium Myocardium The muscle tissue of the heart. It is composed of striated, involuntary muscle cells connected to form the contractile pump to generate blood flow. Heart: Anatomy ( subendocardium Subendocardium Heart: Anatomy) → resulting in myocardial cell death Cell death Injurious stimuli trigger the process of cellular adaptation, whereby cells respond to withstand the harmful changes in their environment. Overwhelmed adaptive mechanisms lead to cell injury. Mild stimuli produce reversible injury. If the stimulus is severe or persistent, injury becomes irreversible. Apoptosis is programmed cell death, a mechanism with both physiologic and pathologic effects. Cell Injury and Death → NSTEMI

Complete occlusion → transmural infarction → STEMI

Clinical Presentation

The classic symptom of MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction in most patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship is acute chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways. However, some patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship may present with more vague symptoms.

Symptoms^[2,11,12]

Typical: 

• Chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways:
  • Retrosternal
  • Dull, squeezing/pressure-like pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
  • May radiate to the left arm Arm The arm, or “upper arm” in common usage, is the region of the upper limb that extends from the shoulder to the elbow joint and connects inferiorly to the forearm through the cubital fossa. It is divided into 2 fascial compartments (anterior and posterior). Arm: Anatomy, shoulder, or jaw Jaw The jaw is made up of the mandible, which comprises the lower jaw, and the maxilla, which comprises the upper jaw. The mandible articulates with the temporal bone via the temporomandibular joint (TMJ). The 4 muscles of mastication produce the movements of the TMJ to ensure the efficient chewing of food. Jaw and Temporomandibular Joint: Anatomy ( radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma rarely goes below the umbilicus or above the mandible Mandible The largest and strongest bone of the face constituting the lower jaw. It supports the lower teeth. Jaw and Temporomandibular Joint: Anatomy)
  • Usually constant, lasting ≥ 20–30 minutes 
  • Levine’s sign: clenched hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy over chest/ sternum Sternum A long, narrow, and flat bone commonly known as breastbone occurring in the midsection of the anterior thoracic segment or chest region, which stabilizes the rib cage and serves as the point of origin for several muscles that move the arms, head, and neck. Chest Wall: Anatomy when individual having chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways is asked to localize the sensation
  • Suggestive of ACS: rest angina, new-onset chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways that limits physical activity, escalating chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways with ↑ frequency and duration
• Angina equivalents: discomfort in the chest, shoulders, arms, neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess, back, upper abdomen, or jaw Jaw The jaw is made up of the mandible, which comprises the lower jaw, and the maxilla, which comprises the upper jaw. The mandible articulates with the temporal bone via the temporomandibular joint (TMJ). The 4 muscles of mastication produce the movements of the TMJ to ensure the efficient chewing of food. Jaw and Temporomandibular Joint: Anatomy; shortness of breath Shortness of breath Dyspnea is the subjective sensation of breathing discomfort. Dyspnea is a normal manifestation of heavy physical or psychological exertion, but also may be caused by underlying conditions (both pulmonary and extrapulmonary). Dyspnea/ dyspnea Dyspnea Dyspnea is the subjective sensation of breathing discomfort. Dyspnea is a normal manifestation of heavy physical or psychological exertion, but also may be caused by underlying conditions (both pulmonary and extrapulmonary). Dyspnea and fatigue Fatigue The state of weariness following a period of exertion, mental or physical, characterized by a decreased capacity for work and reduced efficiency to respond to stimuli. Fibromyalgia
• Diaphoresis
• Nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics

Associated symptoms:

• Dizziness Dizziness An imprecise term which may refer to a sense of spatial disorientation, motion of the environment, or lightheadedness. Lateral Medullary Syndrome (Wallenberg Syndrome)
• “Indigestion” and/or vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia
• Syncope Syncope Syncope is a short-term loss of consciousness and loss of postural stability followed by spontaneous return of consciousness to the previous neurologic baseline without the need for resuscitation. The condition is caused by transient interruption of cerebral blood flow that may be benign or related to a underlying life-threatening condition. Syncope
• Epigastric pain Epigastric pain Mallory-Weiss Syndrome (Mallory-Weiss Tear) (with inferior-wall MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction)
• Palpitations Palpitations Ebstein’s Anomaly

Atypical presentation more common in women, the elderly, or patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus:

• Absence of chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways or atypical locations/ quality Quality Activities and programs intended to assure or improve the quality of care in either a defined medical setting or a program. The concept includes the assessment or evaluation of the quality of care; identification of problems or shortcomings in the delivery of care; designing activities to overcome these deficiencies; and follow-up monitoring to ensure effectiveness of corrective steps. Quality Measurement and Improvement
• May present with only the usual associated symptoms

Compared to stable angina Stable angina Persistent and reproducible chest discomfort usually precipitated by a physical exertion that dissipates upon cessation of such an activity. The symptoms are manifestations of myocardial ischemia. Stable and Unstable Angina (chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways on exertion/stress), unstable angina Unstable angina Precordial pain at rest, which may precede a myocardial infarction. Stable and Unstable Angina:

• Occurs at rest or with previously tolerated levels of exertion
• Has no predictable pattern
• Is not relieved with rest or nitroglycerin Nitroglycerin A volatile vasodilator which relieves angina pectoris by stimulating guanylate cyclase and lowering cytosolic calcium. It is also sometimes used for tocolysis and explosives. Nitrates

Physical examination^[11,15]

• Vitals:
  • Tachycardia Tachycardia Abnormally rapid heartbeat, usually with a heart rate above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia. Sepsis in Children
  • Bradycardia Bradycardia Bradyarrhythmia is a rhythm in which the heart rate is less than 60/min. Bradyarrhythmia can be physiologic, without symptoms or hemodynamic change. Pathologic bradyarrhythmia results in reduced cardiac output and hemodynamic instability causing syncope, dizziness, or dyspnea. Bradyarrhythmias with right coronary artery Right coronary artery Heart: Anatomy (RCA) occlusion (supplies the sinoatrial (SA) and atrioventricular (AV) nodes)
  • Hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension
• Cardiovascular:
  • S3 S3 Heart Sounds heart sound (early diastolic sound heard at the end of rapid ventricular filling Ventricular filling Cardiac Cycle)
  • S4 S4 Heart Sounds heart sound (late diastolic sound heard at the onset of atrial contraction)
  • Jugular venous distention: RCA occlusion → right-sided heart failure Right-Sided Heart Failure Ebstein’s Anomaly (HF)
  • Hepatic congestion: RCA occlusion → right-sided HF
• Pulmonary edema Pulmonary edema Pulmonary edema is a condition caused by excess fluid within the lung parenchyma and alveoli as a consequence of a disease process. Based on etiology, pulmonary edema is classified as cardiogenic or noncardiogenic. Patients may present with progressive dyspnea, orthopnea, cough, or respiratory failure. Pulmonary Edema: left coronary artery Left coronary artery Heart: Anatomy occlusion → left-sided HF:
  • Crackles/ rales Rales Respiratory Syncytial Virus
  • Wheezing Wheezing Wheezing is an abnormal breath sound characterized by a whistling noise that can be relatively high-pitched and shrill (more common) or coarse. Wheezing is produced by the movement of air through narrowed or compressed small (intrathoracic) airways. Wheezing
• Skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions:
  • Cool
  • Pale or cyanotic
  • Diaphoretic

Diagnosis

The approach to diagnosis may vary according to practice location. The following information is based on management guidelines from the American Heart Association American Heart Association A voluntary organization concerned with the prevention and treatment of heart and vascular diseases. Heart Failure/American College of Cardiology, the National Institute for Health and Care Excellence, and the European Society of Cardiology.

The goals of the initial evaluation are to identify life-threatening etiologies and ensure stability of the individual. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship presenting with acute chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways are evaluated with ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) (obtained within 10 minutes). 

ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG)^{[2,5,11,12,15]}

• ACS is not ruled out with a normal initial ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG):
  • Serial ECGs are recommended, especially if symptoms persist, until ACS is ruled out.
  • Consider adding leads V7–V9 to rule out posterior MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction.
• Findings in unstable angina Unstable angina Precordial pain at rest, which may precede a myocardial infarction. Stable and Unstable Angina:
  • May be normal (or show nonspecific changes)
  • Transient evidence of subendocardial ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage:
    • ST-segment depression 
    • T-wave flattening
    • T-wave inversion
• Findings in NSTEMI:
  • ST depression (not elevation) in 2 contiguous leads
  • Inverted T waves in 2 contiguous leads
  • May be normal or have nonspecific changes
• Findings in STEMI:
  • Evolution:
    • Tall, peaked (hyperacute) T waves may be seen early in the course.
    • ≥ 1-mm ST elevation in ≥ 2 contiguous leads
    • Reciprocal ST depression
    • Pathologic Q waves typically emerge between 6 and 16 hours after symptom onset
    • T-wave inversion follows, with Q waves getting deeper
    • ST-segment normalization, usually still with T-wave inversion
    • T-wave normalization over several hours to days
  • New LBBB LBBB Bundle Branch and Fascicular Blocks and symptoms → STEMI until proven otherwise
• If ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) shows ST–T-wave depression in II, III, aVF (inferior wall ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage):
  • Obtain leads V4R, V5R, and V6R (to check for right ventricular infarct Infarct Area of necrotic cells in an organ, arising mainly from hypoxia and ischemia Ischemic Cell Damage).
  • Obtain leads V7–V9 (to check for posterior MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction).
• ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) also assists in identifying nonischemic causes, such as pericarditis Pericarditis Pericarditis is an inflammation of the pericardium, often with fluid accumulation. It can be caused by infection (often viral), myocardial infarction, drugs, malignancies, metabolic disorders, autoimmune disorders, or trauma. Acute, subacute, and chronic forms exist. Pericarditis, myocarditis Myocarditis Myocarditis is an inflammatory disease of the myocardium, which may occur alone or in association with a systemic process. There are numerous etiologies of myocarditis, but all lead to inflammation and myocyte injury, most often leading to signs and symptoms of heart failure. Myocarditis, and new arrhythmia.
  • Normal → add other tests (labs)
  • Diffuse ST elevation → pericarditis Pericarditis Pericarditis is an inflammation of the pericardium, often with fluid accumulation. It can be caused by infection (often viral), myocardial infarction, drugs, malignancies, metabolic disorders, autoimmune disorders, or trauma. Acute, subacute, and chronic forms exist. Pericarditis
  • New arrhythmia → treat according to guidelines

Laboratory evaluation^{[2,11,15,17,18]}

Cardiac enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body’s constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes: 

• Structural proteins Structural proteins Proteins and Peptides in the heart that are released as a result of myocardial injury
• High-sensitivity cardiac troponin ( hs HS Hypertrophic scars and keloids are raised, red, and rigid (3 rs) scars that develop during cutaneous wound healing and are characterized by a local abnormal proliferation of fibroblasts with over-production of collagen. Over-expression of growth factors and decreased production of molecules that promote matrix breakdown appear to be involved in the etiology. Hypertrophic and Keloid Scars–cTn), which more accurately detects myocardial injury, is preferred.
  • Detection of hs HS Hypertrophic scars and keloids are raised, red, and rigid (3 rs) scars that develop during cutaneous wound healing and are characterized by a local abnormal proliferation of fibroblasts with over-production of collagen. Over-expression of growth factors and decreased production of molecules that promote matrix breakdown appear to be involved in the etiology. Hypertrophic and Keloid Scars–cTn takes less time (from onset of chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways) than conventional troponin assays.
  • Hs-cTn is superior to CK-MB in diagnosing myocardial injury.
  • Serum levels:
    • Start to ↑ within 2–3 hours after the onset of chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
    • Peak levels at 12–48 hours
    • Return to baseline over 4–10 days
  • Serial lab draws are used to assess for a rise and fall in levels (recheck in 1–3 hours).
  • The degree of ↑ correlates with the size of the infarct Infarct Area of necrotic cells in an organ, arising mainly from hypoxia and ischemia Ischemic Cell Damage.
  • Can be ↑ as the result of causes of coronary ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage other than acute MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction:
    • Arrhythmia
    • Cocaine Cocaine An alkaloid ester extracted from the leaves of plants including coca. It is a local anesthetic and vasoconstrictor and is clinically used for that purpose, particularly in the eye, ear, nose, and throat. It also has powerful central nervous system effects similar to the amphetamines and is a drug of abuse. Cocaine, like amphetamines, acts by multiple mechanisms on brain catecholaminergic neurons; the mechanism of its reinforcing effects is thought to involve inhibition of dopamine uptake. Local Anesthetics
    • PCI
    • Coronary embolism
    • Aortic dissection Aortic dissection Aortic dissection occurs due to shearing stress from pulsatile pressure causing a tear in the tunica intima of the aortic wall. This tear allows blood to flow into the media, creating a “false lumen.” Aortic dissection is most commonly caused by uncontrolled hypertension. Aortic Dissection
  • Can be ↑ with noncoronary ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage or myocardial injury:
    • Electrical shock Shock Shock is a life-threatening condition associated with impaired circulation that results in tissue hypoxia. The different types of shock are based on the underlying cause: distributive (↑ cardiac output (CO), ↓ systemic vascular resistance (SVR)), cardiogenic (↓ CO, ↑ SVR), hypovolemic (↓ CO, ↑ SVR), obstructive (↓ CO), and mixed. Types of Shock
    • Hypoxia Hypoxia Sub-optimal oxygen levels in the ambient air of living organisms. Ischemic Cell Damage
    • Myocarditis Myocarditis Myocarditis is an inflammatory disease of the myocardium, which may occur alone or in association with a systemic process. There are numerous etiologies of myocarditis, but all lead to inflammation and myocyte injury, most often leading to signs and symptoms of heart failure. Myocarditis
    • Takotsubo cardiomyopathy Takotsubo Cardiomyopathy Takotsubo cardiomyopathy (also known as stress cardiomyopathy, or “broken heart syndrome”) is a type of non-ischemic cardiomyopathy in which there is transient regional systolic dysfunction of the left ventricle. Patients present with symptoms of acute coronary syndrome, including chest pressure and shortness of breath. Takotsubo Cardiomyopathy: sudden, temporary weakening of the heart muscle (usually related to a stressor)
  • Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with CKD CKD Chronic kidney disease (CKD) is kidney impairment that lasts for ≥ 3 months, implying that it is irreversible. Hypertension and diabetes are the most common causes; however, there are a multitude of other etiologies. In the early to moderate stages, CKD is usually asymptomatic and is primarily diagnosed by laboratory abnormalities. Chronic Kidney Disease:
    • May have stably ↑ levels in the absence of myocardial damage
    • A rise or fall in troponin I Troponin I A troponin complex subunit that inhibits actomyosin ATPase activity thereby disrupting actin and myosin interaction. There are three troponin I subtypes: troponin i1, i2 and i3. Troponin i3 is cardiac-specific whereas troponin i1 and i2 are skeletal subtypes. Troponin i3 is a biomarker for damaged or injured cardiac myocytes and mutations in troponin i3 gene are associated with familial hypertrophic cardiomyopathy. Myocardial Infarction value > 20% over 6–9 hours is indicative of acute MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with end-stage CKD CKD Chronic kidney disease (CKD) is kidney impairment that lasts for ≥ 3 months, implying that it is irreversible. Hypertension and diabetes are the most common causes; however, there are a multitude of other etiologies. In the early to moderate stages, CKD is usually asymptomatic and is primarily diagnosed by laboratory abnormalities. Chronic Kidney Disease.
• CK-MB isoenzyme:
  • Not typically ordered
  • Less sensitive and specific than troponin:
    • ↑ within 3–6 hours after chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
    • Peaks within 12–24 hours
    • Normalizes 48–72 hours after MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction
  • Continued ↑ after 72 hours is diagnostic of reinfarction.
  • The degree of ↑ in CK-MB correlates with the size of the infarct Infarct Area of necrotic cells in an organ, arising mainly from hypoxia and ischemia Ischemic Cell Damage.

Other tests (to assess associated risks or triggering factors, and prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas):

• B type natriuretic peptide ( BNP BNP A peptide that is secreted by the brain and the heart atria, stored mainly in cardiac ventricular myocardium. It can cause natriuresis; diuresis; vasodilation; and inhibits secretion of renin and aldosterone. It improves heart function. It contains 32 amino acids. Renal Sodium and Water Regulation) or N-terminal pro-BNP (NT-proBNP)
• Lipid panel
• Metabolic panel
• Hemoglobin A_1c
• Complete blood count
• Toxicology testing (e.g., cocaine Cocaine An alkaloid ester extracted from the leaves of plants including coca. It is a local anesthetic and vasoconstrictor and is clinically used for that purpose, particularly in the eye, ear, nose, and throat. It also has powerful central nervous system effects similar to the amphetamines and is a drug of abuse. Cocaine, like amphetamines, acts by multiple mechanisms on brain catecholaminergic neurons; the mechanism of its reinforcing effects is thought to involve inhibition of dopamine uptake. Local Anesthetics, methamphetamine Methamphetamine A central nervous system stimulant and sympathomimetic with actions and uses similar to dextroamphetamine. The smokable form is a drug of abuse and is referred to as crank, crystal, crystal meth, ice, and speed. Stimulants)

ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) and lab comparison within acute coronary syndrome

The following table compares unstable angina Unstable angina Precordial pain at rest, which may precede a myocardial infarction. Stable and Unstable Angina, NSTEMI, and STEMI on the basis of clinical features, ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG), and laboratory findings.

Imaging^{[2,11,15,18,28]}

• Chest X-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests: often ordered to evaluate for other causes of chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
  • Potential findings consistent with alternative causes of chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways:
    • Pneumonia Pneumonia Pneumonia or pulmonary inflammation is an acute or chronic inflammation of lung tissue. Causes include infection with bacteria, viruses, or fungi. In more rare cases, pneumonia can also be caused through toxic triggers through inhalation of toxic substances, immunological processes, or in the course of radiotherapy. Pneumonia
    • Pneumothorax Pneumothorax A pneumothorax is a life-threatening condition in which air collects in the pleural space, causing partial or full collapse of the lung. A pneumothorax can be traumatic or spontaneous. Patients present with a sudden onset of sharp chest pain, dyspnea, and diminished breath sounds on exam. Pneumothorax
    • Mediastinal widening → aortic dissection Aortic dissection Aortic dissection occurs due to shearing stress from pulsatile pressure causing a tear in the tunica intima of the aortic wall. This tear allows blood to flow into the media, creating a “false lumen.” Aortic dissection is most commonly caused by uncontrolled hypertension. Aortic Dissection
  • Presence of cardiomegaly Cardiomegaly Enlargement of the heart, usually indicated by a cardiothoracic ratio above 0. 50. Heart enlargement may involve the right, the left, or both heart ventricles or heart atria. Cardiomegaly is a nonspecific symptom seen in patients with chronic systolic heart failure (heart failure) or several forms of cardiomyopathies. Ebstein’s Anomaly and pulmonary congestion (due to heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction. Total Anomalous Pulmonary Venous Return (TAPVR)) can be identified.

• Transthoracic echocardiography Transthoracic Echocardiography Imaging of the Heart and Great Vessels ( TTE TTE Imaging of the Heart and Great Vessels):
  • Recommended in the initial evaluation of those with intermediate risk for major CAD events
  • Left ventricular ejection fraction Ejection fraction Cardiac Cycle (LVEF) is the best predictor of survival in STEMI.
  • New regional wall motion abnormalities can be visualized.
  • Can evaluate for complications of MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction:
    • Free-wall rupture Free-wall rupture Myocardial Infarction
    • Ventricular septal rupture Ventricular septal rupture Laceration or tearing of the ventricular septum, usually caused by myocardial infarction. Myocardial Infarction
    • Mitral regurgitation Regurgitation Gastroesophageal Reflux Disease (GERD)
    • Aneurysm Aneurysm An aneurysm is a bulging, weakened area of a blood vessel that causes an abnormal widening of its diameter > 1.5 times the size of the native vessel. Aneurysms occur more often in arteries than in veins and are at risk of dissection and rupture, which can be life-threatening. Thoracic Aortic Aneurysms formation
    • Presence of a thrombus
• Coronary CT angiography Angiography Radiography of blood vessels after injection of a contrast medium. Cardiac Surgery:
  • May be utilized for high-risk patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship in an attempt to avoid coronary angiography Angiography Radiography of blood vessels after injection of a contrast medium. Cardiac Surgery (e.g., bleeding risk, poor vascular access)
  • Benefits:
    • Rapid
    • Can exclude obstructive CAD
    • Can identify high-risk plaque Plaque Primary Skin Lesions and plaque Plaque Primary Skin Lesions burden
    • May be combined with functional flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure reserve or perfusion studies to assess the significance of effect of stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) on the myocardium Myocardium The muscle tissue of the heart. It is composed of striated, involuntary muscle cells connected to form the contractile pump to generate blood flow. Heart: Anatomy

Diagnostic approach

Principles:^[11]

• If  STEMI is detected in the initial evaluation, guidelines for STEMI should be followed. 
• In those presenting with unstable angina Unstable angina Precordial pain at rest, which may precede a myocardial infarction. Stable and Unstable Angina/NSTEMI:
  • Routine use of clinical decision pathways based on risk is recommended. 
  • Assessment of the cardiac risk is first performed and then followed by testing/procedure, which will likely benefit the patient. 

Diagnosis of STEMI:^[12]

• Diagnosed by:
  • Presenting symptoms can be chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, dyspnea Dyspnea Dyspnea is the subjective sensation of breathing discomfort. Dyspnea is a normal manifestation of heavy physical or psychological exertion, but also may be caused by underlying conditions (both pulmonary and extrapulmonary). Dyspnea, arrhythmia, cardiac arrest Cardiac arrest Cardiac arrest is the sudden, complete cessation of cardiac output with hemodynamic collapse. Patients present as pulseless, unresponsive, and apneic. Rhythms associated with cardiac arrest are ventricular fibrillation/tachycardia, asystole, or pulseless electrical activity. Cardiac Arrest, or other angina equivalents.
  • ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) findings (as outlined above)
  • Laboratory tests ( hs HS Hypertrophic scars and keloids are raised, red, and rigid (3 rs) scars that develop during cutaneous wound healing and are characterized by a local abnormal proliferation of fibroblasts with over-production of collagen. Over-expression of growth factors and decreased production of molecules that promote matrix breakdown appear to be involved in the etiology. Hypertrophic and Keloid Scars–cTn)
  • Additional studies:
    • Complete blood count, metabolic panel including renal function, coagulation studies Coagulation studies Coagulation studies are a group of hematologic laboratory studies that reflect the function of blood vessels, platelets, and coagulation factors, which all interact with one another to achieve hemostasis. Coagulation studies are usually ordered to evaluate patients with bleeding or hypercoagulation disorders. Coagulation Studies
    • Additional labs as indicated
    • Echocardiography Echocardiography Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic. Tricuspid Valve Atresia (TVA) if with suspected valvular heart disease, heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction. Total Anomalous Pulmonary Venous Return (TAPVR)
• Next steps:
  • Continuous telemetry Telemetry Transmission of the readings of instruments to a remote location by means of wires, radio waves, or other means. Crush Syndrome
  • Serial cardiac enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body’s constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes
  • Assess for other life-threatening conditions (e.g., heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction. Total Anomalous Pulmonary Venous Return (TAPVR), aortic dissection Aortic dissection Aortic dissection occurs due to shearing stress from pulsatile pressure causing a tear in the tunica intima of the aortic wall. This tear allows blood to flow into the media, creating a “false lumen.” Aortic dissection is most commonly caused by uncontrolled hypertension. Aortic Dissection)
  • Assess for bleeding risk and coagulation disorders
  • Stabilize patient and initiate routine medical therapy
• Choose reperfusion strategy.

Diagnosis of NSTEMI/ unstable angina Unstable angina Precordial pain at rest, which may precede a myocardial infarction. Stable and Unstable Angina:^{[11,13,15,18,25]} 

• Diagnosed by:
  • Presenting symptoms
  • ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) findings (e.g., ST-segment depression, T-wave inversions, or can be normal)
  • Laboratory test ( hs HS Hypertrophic scars and keloids are raised, red, and rigid (3 rs) scars that develop during cutaneous wound healing and are characterized by a local abnormal proliferation of fibroblasts with over-production of collagen. Over-expression of growth factors and decreased production of molecules that promote matrix breakdown appear to be involved in the etiology. Hypertrophic and Keloid Scars–cTn: normal in unstable angina Unstable angina Precordial pain at rest, which may precede a myocardial infarction. Stable and Unstable Angina, elevated in NSTEMI)
  • Additional labs including complete blood count, metabolic panel including renal function, coagulation studies Coagulation studies Coagulation studies are a group of hematologic laboratory studies that reflect the function of blood vessels, platelets, and coagulation factors, which all interact with one another to achieve hemostasis. Coagulation studies are usually ordered to evaluate patients with bleeding or hypercoagulation disorders. Coagulation Studies
  • Additional imaging as indicated
• Next steps:
  • Continuous telemetry Telemetry Transmission of the readings of instruments to a remote location by means of wires, radio waves, or other means. Crush Syndrome
  • Serial cardiac enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body’s constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes
  • Assess for other life-threatening conditions (e.g., heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction. Total Anomalous Pulmonary Venous Return (TAPVR), aortic dissection Aortic dissection Aortic dissection occurs due to shearing stress from pulsatile pressure causing a tear in the tunica intima of the aortic wall. This tear allows blood to flow into the media, creating a “false lumen.” Aortic dissection is most commonly caused by uncontrolled hypertension. Aortic Dissection).
  • Assess for bleeding risk and coagulation disorders.
  • Stabilize patient and initiate routine medical therapy.
  • Risk-stratify:
    • Determines the short-term adverse effects
    • Determines further cardiac testing and management needed
• Different scoring systems developed for risk stratification: 
  • HEART score:
    • History, ECG, Age, Risk factors, Troponin
    • One of the most commonly used
    • Low-risk (a score of ≤ 3): low major adverse cardiovascular events (MACE) rate (1.7%)
    • Moderate-risk (score of 4–6): MACE rate of approximately 12%–17% 
    • High-risk (≥ 7): MACE rate of 50%–65%
  • TIMI score:^[14]
    • Thrombolysis In Myocardial Infarction
    • Determines probability Probability Probability is a mathematical tool used to study randomness and provide predictions about the likelihood of something happening. There are several basic rules of probability that can be used to help determine the probability of multiple events happening together, separately, or sequentially. Basics of Probability of ischemic events or mortality Mortality All deaths reported in a given population. Measures of Health Status in unstable angina Unstable angina Precordial pain at rest, which may precede a myocardial infarction. Stable and Unstable Angina or NSTEMI using 7 factors (which are assigned 1 point each)
    • HEART score helps stratify undifferentiated chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways better than the TIMI score.
  • GRACE ACS risk score:
    • Global Registry of Acute Coronary Events
    • Estimates in-hospital and 6-month mortality Mortality All deaths reported in a given population. Measures of Health Status rate in ACS 
    • Variables: age, heart rate Heart rate The number of times the heart ventricles contract per unit of time, usually per minute. Cardiac Physiology, systolic blood pressure, ST-segment deviation, renal function, congestive heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction. Total Anomalous Pulmonary Venous Return (TAPVR), cardiac arrest Cardiac arrest Cardiac arrest is the sudden, complete cessation of cardiac output with hemodynamic collapse. Patients present as pulseless, unresponsive, and apneic. Rhythms associated with cardiac arrest are ventricular fibrillation/tachycardia, asystole, or pulseless electrical activity. Cardiac Arrest, and elevated biomarkers
    • Recommended in UK (National Institute for Health and Care Excellence)^[13,15] and Europe (European Society of Cardiology)^[18]

Management

Approach to management may vary according to practice location. The following information is based on the management guidelines of the American Heart Association American Heart Association A voluntary organization concerned with the prevention and treatment of heart and vascular diseases. Heart Failure/American College of Cardiology, the National Institute for Health and Care Excellence, and the European Society of Cardiology. 

Routine medical therapy in ACS

Prompt recognition of the diagnosis of acute MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction is imperative in order to realize the benefit from reperfusion therapy. 

Prompt recognition of the diagnosis of acute MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction is imperative in order to realize the benefit from reperfusion therapy. All forms of ACS have similar medical principles, except that in unstable angina Unstable angina Precordial pain at rest, which may precede a myocardial infarction. Stable and Unstable Angina and NSTEMI, fibrinolysis has not shown benefit.

• Initiate medical therapy, preferably within 20 minutes after presentation.
• Admission to coronary care unit/chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways unit
• Continuous ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) or telemetry Telemetry Transmission of the readings of instruments to a remote location by means of wires, radio waves, or other means. Crush Syndrome monitoring

Anti-ischemic therapy:^{[12,15,18,23,25]}

• Oxygen support in:
  • O₂ saturation < 94% (< 90%, per European guidelines)
  • Respiratory distress present
  • Heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction. Total Anomalous Pulmonary Venous Return (TAPVR) present
  • Other high-risk features of hypoxia Hypoxia Sub-optimal oxygen levels in the ambient air of living organisms. Ischemic Cell Damage
• Nitrates Nitrates Nitrates are a class of medications that cause systemic vasodilation (veins > arteries) by smooth muscle relaxation. Nitrates are primarily indicated for the treatment of angina, where preferential venodilation causes pooling of blood, decreased preload, and ultimately decreased myocardial O2 demand. Nitrates: vasodilation Vasodilation The physiological widening of blood vessels by relaxing the underlying vascular smooth muscle. Pulmonary Hypertension Drugs → ↓ preload Preload Cardiac Mechanics → ↓ oxygen demand → ↓ symptoms:
  • Sublingual nitroglycerin Nitroglycerin A volatile vasodilator which relieves angina pectoris by stimulating guanylate cyclase and lowering cytosolic calcium. It is also sometimes used for tocolysis and explosives. Nitrates (maximum: 3 tablets)
  • IV nitroglycerin Nitroglycerin A volatile vasodilator which relieves angina pectoris by stimulating guanylate cyclase and lowering cytosolic calcium. It is also sometimes used for tocolysis and explosives. Nitrates if with persistent pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension, heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction. Total Anomalous Pulmonary Venous Return (TAPVR)
  • May cause hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension: avoid if with low BP, if individual is on phosphodiesterase inhibitor, or in right ventricular infarction (inferior-wall MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction) 
• Morphine Morphine The principal alkaloid in opium and the prototype opiate analgesic and narcotic. Morphine has widespread effects in the central nervous system and on smooth muscle. Opioid Analgesics:
  • ↓ Anxiety Anxiety Feelings or emotions of dread, apprehension, and impending disaster but not disabling as with anxiety disorders. Generalized Anxiety Disorder and the adrenergic drive that causes further vasoconstriction Vasoconstriction The physiological narrowing of blood vessels by contraction of the vascular smooth muscle. Vascular Resistance, Flow, and Mean Arterial Pressure
  • Give only if with unreasonable amount of pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways (relief of ischemic pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways  →  ↓ preload Preload Cardiac Mechanics)
  • Indiscriminate use can lead to more adverse effects such as respiratory depression (higher risk of death).
  • Give at an initial dose of 2–4 mg IV.^[24]
• Beta-blockers Beta-blockers Drugs that bind to but do not activate beta-adrenergic receptors thereby blocking the actions of beta-adrenergic agonists. Adrenergic beta-antagonists are used for treatment of hypertension, cardiac arrhythmias, angina pectoris, glaucoma, migraine headaches, and anxiety. Class 2 Antiarrhythmic Drugs (Beta Blockers):
  • Start within 24 hours
  • ↓ Heart rate Heart rate The number of times the heart ventricles contract per unit of time, usually per minute. Cardiac Physiology and contractility → ↓ oxygen demand→ ↓ symptoms
  • Cardioselective medications (e.g., metoprolol Metoprolol A selective adrenergic beta-1 blocking agent that is commonly used to treat angina pectoris; hypertension; and cardiac arrhythmias. Antiadrenergic Drugs) are preferred.
  • For heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction. Total Anomalous Pulmonary Venous Return (TAPVR)/reduced systolic function (not decompensated): use bisoprolol Bisoprolol A cardioselective beta-1 adrenergic blocker. It is effective in the management of hypertension and angina pectoris. Class 2 Antiarrhythmic Drugs (Beta Blockers), sustained-release metoprolol Metoprolol A selective adrenergic beta-1 blocking agent that is commonly used to treat angina pectoris; hypertension; and cardiac arrhythmias. Antiadrenergic Drugs, or carvedilol Carvedilol A carbazole and propanol derivative that acts as a non-cardioselective beta blocker and vasodilator. It has blocking activity for alpha 1 adrenergic receptors and, at higher doses, may function as a blocker of calcium channels; it also has antioxidant properties. Carvedilol is used in the treatment of hypertension; angina pectoris; and heart failure. It can also reduce the risk of death following myocardial infarction. Class 2 Antiarrhythmic Drugs (Beta Blockers).
  • Avoid in heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction. Total Anomalous Pulmonary Venous Return (TAPVR) or cardiogenic shock Cardiogenic shock Shock resulting from diminution of cardiac output in heart disease. Types of Shock, bradycardia Bradycardia Bradyarrhythmia is a rhythm in which the heart rate is less than 60/min. Bradyarrhythmia can be physiologic, without symptoms or hemodynamic change. Pathologic bradyarrhythmia results in reduced cardiac output and hemodynamic instability causing syncope, dizziness, or dyspnea. Bradyarrhythmias, PR interval PR interval Electrocardiogram (ECG) > 0.24 second, 2nd- or 3rd-degree heart block, severe reactive airway Airway ABCDE Assessment disease or active asthma Asthma Asthma is a chronic inflammatory respiratory condition characterized by bronchial hyperresponsiveness and airflow obstruction. The disease is believed to result from the complex interaction of host and environmental factors that increase disease predisposition, with inflammation causing symptoms and structural changes. Patients typically present with wheezing, cough, and dyspnea. Asthma, cocaine-induced MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction
• Calcium-channel blockers Calcium-Channel Blockers A class of drugs that act by selective inhibition of calcium influx through cellular membranes. Heart Failure and Angina Medication ( CCBs CCBs Calcium channel blockers (CCBS) are a class of medications that inhibit voltage-dependent L-type calcium channels of cardiac and vascular smooth muscle cells. The inhibition of these channels produces vasodilation and myocardial depression. There are 2 major classes of CCBS: dihydropyridines and non-dihydropyridines. Class 4 Antiarrhythmic Drugs (Calcium Channel Blockers)):
  • Nondihydropyridine CCBs CCBs Calcium channel blockers (CCBS) are a class of medications that inhibit voltage-dependent L-type calcium channels of cardiac and vascular smooth muscle cells. The inhibition of these channels produces vasodilation and myocardial depression. There are 2 major classes of CCBS: dihydropyridines and non-dihydropyridines. Class 4 Antiarrhythmic Drugs (Calcium Channel Blockers) if with contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation to beta-blockers Beta-blockers Drugs that bind to but do not activate beta-adrenergic receptors thereby blocking the actions of beta-adrenergic agonists. Adrenergic beta-antagonists are used for treatment of hypertension, cardiac arrhythmias, angina pectoris, glaucoma, migraine headaches, and anxiety. Class 2 Antiarrhythmic Drugs (Beta Blockers)
  • Also an option for recurrent ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage
• Statin therapy (high-intensity therapy regardless of LDL):
  • Benefits:^[26]
    • Suppresses the secretion Secretion Coagulation Studies of inflammatory mediators 
    • Reduces plaque Plaque Primary Skin Lesions volume
    • Thickens the fibrous Fibrous Fibrocystic Change cap
  • Options:
    • Atorvastatin Atorvastatin A pyrrole and heptanoic acid derivative, hydroxymethylglutaryl-CoA reductase inhibitor (statin), and anticholesteremic agent that is used to reduce serum levels of ldl-cholesterol; apolipoprotein b; and triglycerides. It is used to increase serum levels of hdl-cholesterol in the treatment of hyperlipidemias, and for the prevention of cardiovascular diseases in patients with multiple risk factors. Statins 40–80 mg daily 
    • Rosuvastatin Rosuvastatin A hydroxymethylglutaryl-coa-reductase inhibitor, or statin, that reduces the plasma concentrations of ldl-cholesterol; apolipoprotein b, and triglycerides while increasing hdl-cholesterol levels in patients with hypercholesterolemia and those at risk for cardiovascular diseases. Statins 20–40 mg daily

Antithrombotic therapy:^{[12–14,18,25]}

• Dual antiplatelet therapy (DAPT) with aspirin Aspirin The prototypical analgesic used in the treatment of mild to moderate pain. It has anti-inflammatory and antipyretic properties and acts as an inhibitor of cyclooxygenase which results in the inhibition of the biosynthesis of prostaglandins. Aspirin also inhibits platelet aggregation and is used in the prevention of arterial and venous thrombosis. Nonsteroidal Antiinflammatory Drugs (NSAIDs) and a platelet P2Y₁₂ receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors blocker:
  • Most STEMI cases and NSTEMI/ unstable angina Unstable angina Precordial pain at rest, which may precede a myocardial infarction. Stable and Unstable Angina receive DAPT.
  • Selection Selection Lymphocyte activation by a specific antigen thus triggering clonal expansion of lymphocytes already capable of mounting an immune response to the antigen. B cells: Types and Functions depends on the reperfusion strategy and patient characteristics.
• Aspirin Aspirin The prototypical analgesic used in the treatment of mild to moderate pain. It has anti-inflammatory and antipyretic properties and acts as an inhibitor of cyclooxygenase which results in the inhibition of the biosynthesis of prostaglandins. Aspirin also inhibits platelet aggregation and is used in the prevention of arterial and venous thrombosis. Nonsteroidal Antiinflammatory Drugs (NSAIDs):
  • Given in all cases, unless with contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation
  • Initial aspirin Aspirin The prototypical analgesic used in the treatment of mild to moderate pain. It has anti-inflammatory and antipyretic properties and acts as an inhibitor of cyclooxygenase which results in the inhibition of the biosynthesis of prostaglandins. Aspirin also inhibits platelet aggregation and is used in the prevention of arterial and venous thrombosis. Nonsteroidal Antiinflammatory Drugs (NSAIDs) dose given: 100–325 mg (lower dose on discharge: 75–100 mg daily)
• Platelet P2Y₁₂ receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors blocker options:
  • Prasugrel Prasugrel A piperazine derivative and platelet aggregation inhibitor that is used to prevent thrombosis in patients with acute coronary syndrome; unstable angina and myocardial infarction, as well as in those undergoing percutaneous coronary interventions. Antiplatelet Drugs:
    • Loading dose Loading Dose Dosage Calculation of 60 mg, then 10 mg daily
    • Not typically recommended if patient is ≥ age 75 or is < 60 kg
    • Should not be used if previous ischemic or hemorrhagic stroke Hemorrhagic stroke Stroke due to rupture of a weakened blood vessel in the brain (e.g., cerebral hemispheres; cerebellum; subarachnoid space). Subarachnoid Hemorrhage, TIA TIA Transient ischemic attack (TIA) is a temporary episode of neurologic dysfunction caused by ischemia without infarction that resolves completely when blood supply is restored. Transient ischemic attack is a neurologic emergency that warrants urgent medical attention. Transient Ischemic Attack (TIA), moderate-to-severe liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy disease, or on anticoagulation Anticoagulation Pulmonary Hypertension Drugs
  • Ticagrelor Ticagrelor An adenosine triphosphate analogue and reversible p2y12 purinoceptor antagonist that inhibits adp-mediated platelet aggregation. It is used for the prevention of thromboembolism by patients with acute coronary syndrome or a history of myocardial infarction. Antiplatelet Drugs:
    • Loading dose Loading Dose Dosage Calculation of 180 mg, then 90 mg twice daily
    • Can cause transient dyspnea Dyspnea Dyspnea is the subjective sensation of breathing discomfort. Dyspnea is a normal manifestation of heavy physical or psychological exertion, but also may be caused by underlying conditions (both pulmonary and extrapulmonary). Dyspnea → rarely requires discontinuation of therapy
    • Should not be used if previous hemorrhagic stroke Hemorrhagic stroke Stroke due to rupture of a weakened blood vessel in the brain (e.g., cerebral hemispheres; cerebellum; subarachnoid space). Subarachnoid Hemorrhage, moderate-to-severe liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy disease, or on anticoagulation Anticoagulation Pulmonary Hypertension Drugs
  • Clopidogrel Clopidogrel A ticlopidine analog and platelet purinergic p2y receptor antagonist that inhibits adenosine diphosphate-mediated platelet aggregation. It is used to prevent thromboembolism in patients with arterial occlusive diseases; myocardial infarction; stroke; or atrial fibrillation. Antiplatelet Drugs:
    • Loading dose Loading Dose Dosage Calculation of 300–600 mg, then 75 mg daily
    • Option if ticagrelor Ticagrelor An adenosine triphosphate analogue and reversible p2y12 purinoceptor antagonist that inhibits adp-mediated platelet aggregation. It is used for the prevention of thromboembolism by patients with acute coronary syndrome or a history of myocardial infarction. Antiplatelet Drugs and prasugrel Prasugrel A piperazine derivative and platelet aggregation inhibitor that is used to prevent thrombosis in patients with acute coronary syndrome; unstable angina and myocardial infarction, as well as in those undergoing percutaneous coronary interventions. Antiplatelet Drugs are not available or are contraindicated
• GPIIb/IIIa inhibitors or GPI (IV eptifibatide Eptifibatide Cyclic peptide that acts as a platelet glycoprotein iib-iiia antagonist, reversibly inhibiting the binding of fibrinogen; von Willebrand factor; and other adhesive molecules to the gpiib-iiia receptors of platelets. It is used in the management of unstable angina and in patients undergoing coronary angioplasty and stenting procedures. Antiplatelet Drugs or tirofiban Tirofiban Tyrosine analog and platelet glycoprotein gpiib-iiia complex antagonist that inhibits platelet aggregation and is used in the treatment of acute coronary syndrome. Antiplatelet Drugs):
  • Not routine, but considered in cases with intermediate- or high-risk features prior to angiography Angiography Radiography of blood vessels after injection of a contrast medium. Cardiac Surgery/ percutaneous coronary intervention Percutaneous coronary intervention A family of percutaneous techniques that are used to manage coronary occlusion, including standard balloon angioplasty (percutaneous transluminal coronary angioplasty), the placement of intracoronary stents, and atheroablative technologies (e.g., atherectomy; endarterectomy; thrombectomy; percutaneous transluminal laser angioplasty). Ptca was the dominant form of pci, before the widespread use of stenting. Cardiac Surgery
  • Not given in those being treated conservatively
  • Bleeding risk should be low.
  • Use should be guided by a cardiologist
• Anticoagulation Anticoagulation Pulmonary Hypertension Drugs (options):
  • Unfractionated heparin Unfractionated heparin A highly acidic mucopolysaccharide formed of equal parts of sulfated d-glucosamine and d-glucuronic acid with sulfaminic bridges. The molecular weight ranges from six to twenty thousand. Heparin occurs in and is obtained from liver, lung, mast cells, etc. , of vertebrates. Its function is unknown, but it is used to prevent blood clotting in vivo and vitro, in the form of many different salts. Anticoagulants ( UFH UFH A highly acidic mucopolysaccharide formed of equal parts of sulfated d-glucosamine and d-glucuronic acid with sulfaminic bridges. The molecular weight ranges from six to twenty thousand. Heparin occurs in and is obtained from liver, lung, mast cells, etc. , of vertebrates. Its function is unknown, but it is used to prevent blood clotting in vivo and vitro, in the form of many different salts. Anticoagulants): preferred if invasive treatment ( angiography Angiography Radiography of blood vessels after injection of a contrast medium. Cardiac Surgery +/– revascularization Revascularization Thromboangiitis Obliterans (Buerger Disease)) will be performed within 48 hours
  • Enoxaparin Enoxaparin Low-molecular-weight fragment of heparin, having a 4-enopyranosuronate sodium structure at the non-reducing end of the chain. It is prepared by depolymerization of the benzylic ester of porcine mucosal heparin. Therapeutically, it is used as an antithrombotic agent. Anticoagulants 
  • Fondaparinux Fondaparinux Synthetic pentasaccharide that mediates the interaction of heparin with antithrombins and inhibits factor Xa; it is used for prevention of venous thromboembolism after surgery. Anticoagulants (STEMI: not for primary PCI)
  • Bivalirudin Bivalirudin Anticoagulants:
    • STEMI: only for PCI
    • NSTEMI: only for early invasive strategy
• Additional recommendations regarding antithrombotic therapy:^[18]
  • Use established bleeding risk scores (e.g., CRUSADE score) before initiating antithrombotic therapy.
  • Use of proton pump Pump ACES and RUSH: Resuscitation Ultrasound Protocols inhibitor with DAPT is recommended.

Other considerations:^[12,18]

• Red blood cell transfusion if hemoglobin < 8 g/dL (or hemoglobin 8–10 g/dL if hemodynamically unstable)
• Treat associated arrhythmias.
• IV saline to ↑ cardiac output Cardiac output The volume of blood passing through the heart per unit of time. It is usually expressed as liters (volume) per minute so as not to be confused with stroke volume (volume per beat). Cardiac Mechanics and perfusion with right ventricular MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction
• Discontinue any nonsteroidal antiinflammatory drugs Nonsteroidal Antiinflammatory Drugs Nonsteroidal antiinflammatory drugs (NSAIDs) are a class of medications consisting of aspirin, reversible NSAIDs, and selective NSAIDs. NSAIDs are used as antiplatelet, analgesic, antipyretic, and antiinflammatory agents. Nonsteroidal Antiinflammatory Drugs (NSAIDs) ( NSAIDs NSAIDS Primary vs Secondary Headaches)

Treatment approach for STEMI

Reperfusion options:^[12–14,23]

• Percutaneous coronary intervention Percutaneous coronary intervention A family of percutaneous techniques that are used to manage coronary occlusion, including standard balloon angioplasty (percutaneous transluminal coronary angioplasty), the placement of intracoronary stents, and atheroablative technologies (e.g., atherectomy; endarterectomy; thrombectomy; percutaneous transluminal laser angioplasty). Ptca was the dominant form of pci, before the widespread use of stenting. Cardiac Surgery (PCI):
  • Improves survival
  • ↓ Rate of intracranial hemorrhage Intracranial hemorrhage Subarachnoid hemorrhage (SAH) is a type of cerebrovascular accident (stroke) resulting from intracranial hemorrhage into the subarachnoid space between the arachnoid and the pia mater layers of the meninges surrounding the brain. Most sahs originate from a saccular aneurysm in the circle of willis but may also occur as a result of trauma, uncontrolled hypertension, vasculitis, anticoagulant use, or stimulant use. Subarachnoid Hemorrhage and recurrent MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction as compared with fibrinolysis
  • Access via the radial or femoral artery Femoral Artery The main artery of the thigh, a continuation of the external iliac artery. Femoral Region and Hernias: Anatomy → diagnostic angiography Angiography Radiography of blood vessels after injection of a contrast medium. Cardiac Surgery → intervention (e.g., stenting, thrombectomy Thrombectomy Surgical removal of an obstructing clot or foreign material from a blood vessel at the point of its formation. Removal of a clot arising from a distant site is called embolectomy. Vascular Surgery) to open the acutely obstructed coronary artery Coronary Artery Truncus Arteriosus
• Fibrinolysis:
  • Tenecteplase Tenecteplase A tissue plasminogen activator enzyme that acts as a fibrinolytic agent; it is used for the dissolution of blood clots, such as those that occur in acute myocardial infarction. Thrombolytics and reteplase Reteplase Thrombolytics (fibrin-specific) are preferred.
  • Streptokinase Streptokinase Streptococcal fibrinolysin. An enzyme produced by hemolytic streptococci. It hydrolyzes amide linkages and serves as an activator of plasminogen. It is used in thrombolytic therapy and is used also in mixtures with streptodornase (streptodornase and streptokinase). Thrombolytics and alteplase Alteplase Thrombolytics are other options.

PCI indications and considerations:^[12–14]

• PCI with stenting is indicated in:
  • Cases where patient is within 120 minutes from a PCI-capable medical facility (symptom onset ≤ 12 hours)
  • Cases of STEMI with cardiogenic shock Cardiogenic shock Shock resulting from diminution of cardiac output in heart disease. Types of Shock
  • Symptom onset > 12 hours with evidence of ongoing ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage
• Contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation:
  • Unable to take DAPT
  • Increased risk of bleeding ( thrombocytopenia Thrombocytopenia Thrombocytopenia occurs when the platelet count is < 150,000 per microliter. The normal range for platelets is usually 150,000-450,000/µL of whole blood. Thrombocytopenia can be a result of decreased production, increased destruction, or splenic sequestration of platelets. Patients are often asymptomatic until platelet counts are < 50,000/µL. Thrombocytopenia, peptic ulcer Peptic ulcer Peptic ulcer disease (PUD) refers to the full-thickness ulcerations of duodenal or gastric mucosa. The ulcerations form when exposure to acid and digestive enzymes overcomes mucosal defense mechanisms. The most common etiologies include Helicobacter pylori (H. pylori) infection and prolonged use of non-steroidal anti-inflammatory drugs (NSAIDs). Peptic Ulcer Disease, severe coagulopathy)
  • Multiple PCI restenosis
• Drug-eluting stents are preferred over bare metal stents.

Fibrinolysis indications and considerations:^[12,13] 

• Fibrinolysis is indicated in cases where the patient is > 120 minutes from a PCI-capable medical facility (symptom onset ≤ 12 hours).
• Absolute contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation:
  • Prior intracranial hemorrhage Intracranial hemorrhage Subarachnoid hemorrhage (SAH) is a type of cerebrovascular accident (stroke) resulting from intracranial hemorrhage into the subarachnoid space between the arachnoid and the pia mater layers of the meninges surrounding the brain. Most sahs originate from a saccular aneurysm in the circle of willis but may also occur as a result of trauma, uncontrolled hypertension, vasculitis, anticoagulant use, or stimulant use. Subarachnoid Hemorrhage ( ICH ICH Intracerebral hemorrhage (ICH) refers to a spontaneous or traumatic bleed into the brain parenchyma and is the 2nd-most common cause of cerebrovascular accidents (CVAs), commonly known as stroke, after ischemic cvas. Intracerebral Hemorrhage)
  • Known structural cerebral vascular lesion
  • Known malignant intracranial neoplasm
  • Ischemic stroke Ischemic Stroke An ischemic stroke (also known as cerebrovascular accident) is an acute neurologic injury that occurs as a result of brain ischemia; this condition may be due to cerebral blood vessel occlusion by thrombosis or embolism, or rarely due to systemic hypoperfusion. Ischemic Stroke within 3 months
  • Suspected aortic dissection Aortic dissection Aortic dissection occurs due to shearing stress from pulsatile pressure causing a tear in the tunica intima of the aortic wall. This tear allows blood to flow into the media, creating a “false lumen.” Aortic dissection is most commonly caused by uncontrolled hypertension. Aortic Dissection
  • Active bleeding or bleeding diathesis Bleeding diathesis Wiskott-Aldrich Syndrome
  • Serious closed-head or facial trauma within 3 months
• Relative contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation:
  • Poorly controlled hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension (systolic BP > 180 mm Hg)
  • Recent internal bleeding (within 4 weeks)
  • Ischemic stroke Ischemic Stroke An ischemic stroke (also known as cerebrovascular accident) is an acute neurologic injury that occurs as a result of brain ischemia; this condition may be due to cerebral blood vessel occlusion by thrombosis or embolism, or rarely due to systemic hypoperfusion. Ischemic Stroke (> 3 months)
  • Prolonged cardiopulmonary resuscitation Resuscitation The restoration to life or consciousness of one apparently dead. . Neonatal Respiratory Distress Syndrome (> 10 minutes)
  • Major surgery within 3 weeks
  • Pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care
  • Active peptic ulcer Peptic ulcer Peptic ulcer disease (PUD) refers to the full-thickness ulcerations of duodenal or gastric mucosa. The ulcerations form when exposure to acid and digestive enzymes overcomes mucosal defense mechanisms. The most common etiologies include Helicobacter pylori (H. pylori) infection and prolonged use of non-steroidal anti-inflammatory drugs (NSAIDs). Peptic Ulcer Disease
  • Current anticoagulant use
• Outcomes:
  • Resolution of ST elevation and improved hemodynamics Hemodynamics The movement and the forces involved in the movement of the blood through the cardiovascular system. Vascular Resistance, Flow, and Mean Arterial Pressure and symptoms → successful reperfusion
  • If reperfusion is not achieved → angiography Angiography Radiography of blood vessels after injection of a contrast medium. Cardiac Surgery in PCI-capable facility

Not a candidate for reperfusion therapy:^[13]

• Presentation late in the illness
• Moribund state 
• Significant comorbidities Comorbidities The presence of co-existing or additional diseases with reference to an initial diagnosis or with reference to the index condition that is the subject of study. Comorbidity may affect the ability of affected individuals to function and also their survival; it may be used as a prognostic indicator for length of hospital stay, cost factors, and outcome or survival. St. Louis Encephalitis Virus/extremely poor health (risks that outweigh benefits)

Indications for CABG CABG Surgical therapy of ischemic coronary artery disease achieved by grafting a section of saphenous vein, internal mammary artery, or other substitute between the aorta and the obstructed coronary artery distal to the obstructive lesion. Cardiac Surgery surgery after MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction:^[12,14]

• Failure of thrombolytics Thrombolytics Thrombolytics, also known as fibrinolytics, include recombinant tissue plasminogen activator (TPa) (i.e., alteplase, reteplase, and tenecteplase), urokinase, and streptokinase. The agents promote the breakdown of a blood clot by converting plasminogen to plasmin, which then degrades fibrin. Thrombolytics or PCI to reperfuse damaged myocardium Myocardium The muscle tissue of the heart. It is composed of striated, involuntary muscle cells connected to form the contractile pump to generate blood flow. Heart: Anatomy
• Hemodynamically important mechanical complications (e.g., rupture, coronary dissection during PCI)
• Anatomy not amenable to PCI
• Severe multivessel disease or left main artery disease
• Life-threatening arrhythmias (usually from persistent ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage)

Treatment approach for NSTEMI and unstable angina Unstable angina Precordial pain at rest, which may precede a myocardial infarction. Stable and Unstable Angina^{[13,14,18,25]}

There are 2 main management strategies:

• Ischemia-guided strategy:
  • Avoids invasive procedures unless there is hemodynamic instability or recurrent/refractory ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage
  • Some cases stabilize with medical therapy, thus avoiding costly procedures.
• Invasive therapy or coronary angiography Angiography Radiography of blood vessels after injection of a contrast medium. Cardiac Surgery (early invasive therapy means within 24 hours, delayed invasive therapy means within 25–72 hours):
  • Rapidly provides stratification by assessing coronary anatomy
  • Generally accepted indications include high-risk features:
    • Angina refractory to pharmacologic therapy
    • Unstable arrhythmias (e.g., ventricular tachyarrhythmias)
    • Depressed ejection fraction Ejection fraction Cardiac Cycle
    • New mitral regurgitation Regurgitation Gastroesophageal Reflux Disease (GERD)
    • Cardiogenic shock Cardiogenic shock Shock resulting from diminution of cardiac output in heart disease. Types of Shock
  • Helps determine candidates for revascularization Revascularization Thromboangiitis Obliterans (Buerger Disease) ( coronary artery Coronary Artery Truncus Arteriosus bypass surgery ( CABG CABG Surgical therapy of ischemic coronary artery disease achieved by grafting a section of saphenous vein, internal mammary artery, or other substitute between the aorta and the obstructed coronary artery distal to the obstructive lesion. Cardiac Surgery) or percutaneous coronary intervention Percutaneous coronary intervention A family of percutaneous techniques that are used to manage coronary occlusion, including standard balloon angioplasty (percutaneous transluminal coronary angioplasty), the placement of intracoronary stents, and atheroablative technologies (e.g., atherectomy; endarterectomy; thrombectomy; percutaneous transluminal laser angioplasty). Ptca was the dominant form of pci, before the widespread use of stenting. Cardiac Surgery (PCI) with stenting)
  • PCI: usually performed for single-vessel disease and clinical instability
  • CABG CABG Surgical therapy of ischemic coronary artery disease achieved by grafting a section of saphenous vein, internal mammary artery, or other substitute between the aorta and the obstructed coronary artery distal to the obstructive lesion. Cardiac Surgery: usually performed for diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus with multivessel disease or multivessel disease with left ventricular dysfunction

Post-MI care^[12–14]

Improved long-term prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas is seen with:

• Antiplatelet therapy to ↓ the risk of recurrent coronary artery Coronary Artery Truncus Arteriosus thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus or, with PCI, coronary artery Coronary Artery Truncus Arteriosus stent thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus
  • Indefinite intake of aspirin Aspirin The prototypical analgesic used in the treatment of mild to moderate pain. It has anti-inflammatory and antipyretic properties and acts as an inhibitor of cyclooxygenase which results in the inhibition of the biosynthesis of prostaglandins. Aspirin also inhibits platelet aggregation and is used in the prevention of arterial and venous thrombosis. Nonsteroidal Antiinflammatory Drugs (NSAIDs)
  • P2Y₁₂ receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors blocker:
    • Medically managed → up to 12 months
    • Coronary stenting → for at least 12 months
• ACEi ACEi A class of drugs whose main indications are the treatment of hypertension and heart failure. They exert their hemodynamic effect mainly by inhibiting the renin-angiotensin system. They also modulate sympathetic nervous system activity and increase prostaglandin synthesis. They cause mainly vasodilation and mild natriuresis without affecting heart rate and contractility. Renin-Angiotensin-Aldosterone System Inhibitors or ARB therapy (if indicated) to prevent remodeling of the left ventricle
• Statin therapy
• Anticoagulation Anticoagulation Pulmonary Hypertension Drugs in the presence of left ventricular thrombus or chronic atrial fibrillation Atrial fibrillation Atrial fibrillation (AF or Afib) is a supraventricular tachyarrhythmia and the most common kind of arrhythmia. It is caused by rapid, uncontrolled atrial contractions and uncoordinated ventricular responses. Atrial Fibrillation to prevent embolization Embolization A method of hemostasis utilizing various agents such as gelfoam, silastic, metal, glass, or plastic pellets, autologous clot, fat, and muscle as emboli. It has been used in the treatment of spinal cord and intracranial arteriovenous malformations, renal arteriovenous fistulas, gastrointestinal bleeding, epistaxis, hypersplenism, certain highly vascular tumors, traumatic rupture of blood vessels, and control of operative hemorrhage. Gastrointestinal Bleeding
• Referral to cardiac rehabilitation

Complications

After MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction, different risks develop as time passes after the acute event. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with type 2 MI Type 2 MI Increased oxygen demand in the myocardium without adequate oxygen supply (whether or not there is underlying atherosclerotic CAD. Myocardial Infarction have a higher prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency of heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction. Total Anomalous Pulmonary Venous Return (TAPVR), kidney disease as a complication of MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction, and atrial fibrillation Atrial fibrillation Atrial fibrillation (AF or Afib) is a supraventricular tachyarrhythmia and the most common kind of arrhythmia. It is caused by rapid, uncontrolled atrial contractions and uncoordinated ventricular responses. Atrial Fibrillation.^[7,10,12]

• Death: 1 of 3 patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship do not survive their initial MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction.
• Potential complications in the first 1–3 days post-MI:
  • Ventricular arrhythmia (most common cause of death)
  • Acute heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction. Total Anomalous Pulmonary Venous Return (TAPVR)
  • Cardiogenic shock Cardiogenic shock Shock resulting from diminution of cardiac output in heart disease. Types of Shock
  • Pericarditis Pericarditis Pericarditis is an inflammation of the pericardium, often with fluid accumulation. It can be caused by infection (often viral), myocardial infarction, drugs, malignancies, metabolic disorders, autoimmune disorders, or trauma. Acute, subacute, and chronic forms exist. Pericarditis:
    • Pleuritic chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways that increases with lying supine
    • Pericardial rub on auscultation
    • Fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
    • Dry cough Dry Cough Strongyloidiasis
    • ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) showing diffuse ST elevations
    • Pericardial effusion Pericardial effusion Fluid accumulation within the pericardium. Serous effusions are associated with pericardial diseases. Hemopericardium is associated with trauma. Lipid-containing effusion (chylopericardium) results from leakage of thoracic duct. Severe cases can lead to cardiac tamponade. Pericardial Effusion and Cardiac Tamponade seen on echocardiogram Echocardiogram Transposition of the Great Arteries
• 3–14 days post-MI:
  • Free-wall rupture Free-wall rupture Myocardial Infarction:
    • Can result in cardiac tamponade Tamponade Pericardial effusion, usually of rapid onset, exceeding ventricular filling pressures and causing collapse of the heart with a markedly reduced cardiac output. Pericarditis or pseudoaneurysm Pseudoaneurysm Not an aneurysm but a well-defined collection of blood and connective tissue outside the wall of a blood vessel or the heart. It is the containment of a ruptured blood vessel or heart, such as sealing a rupture of the left ventricle. False aneurysm is formed by organized thrombus and hematoma in surrounding tissue. Thoracic Aortic Aneurysms formation
    • Incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency is highest during macrophage-mediated removal of necrotic myocardium Myocardium The muscle tissue of the heart. It is composed of striated, involuntary muscle cells connected to form the contractile pump to generate blood flow. Heart: Anatomy.
  • Papillary muscle rupture Papillary muscle rupture Myocardial Infarction:
    • Posteromedial papillary muscle rupture Papillary muscle rupture Myocardial Infarction due to posterior descending artery occlusion
    • Posteromedial-wall rupture → acute mitral regurgitation Regurgitation Gastroesophageal Reflux Disease (GERD)
    • Holosystolic murmur Holosystolic Murmur Tricuspid Valve Atresia (TVA) over the 5th intercostal space at the midclavicular line
    • May present with signs of left-sided heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction. Total Anomalous Pulmonary Venous Return (TAPVR) ( pulmonary edema Pulmonary edema Pulmonary edema is a condition caused by excess fluid within the lung parenchyma and alveoli as a consequence of a disease process. Based on etiology, pulmonary edema is classified as cardiogenic or noncardiogenic. Patients may present with progressive dyspnea, orthopnea, cough, or respiratory failure. Pulmonary Edema, crackles, dyspnea Dyspnea Dyspnea is the subjective sensation of breathing discomfort. Dyspnea is a normal manifestation of heavy physical or psychological exertion, but also may be caused by underlying conditions (both pulmonary and extrapulmonary). Dyspnea)
  • Ventricular septal rupture Ventricular septal rupture Laceration or tearing of the ventricular septum, usually caused by myocardial infarction. Myocardial Infarction:
    • Caused by left anterior descending artery occlusion (LAD supplies the anterior part of the interventricular septum Interventricular Septum Ventricular Septal Defect (VSD))
    • Coincides with macrophage infiltration of the wall
    • May present as a holosystolic murmur Holosystolic Murmur Tricuspid Valve Atresia (TVA) over the left sternal border 
    • May present with signs of right-sided heart failure Right-Sided Heart Failure Ebstein’s Anomaly (e.g., jugular venous distention, peripheral edema Peripheral edema Peripheral edema is the swelling of the lower extremities, namely, legs, feet, and ankles. Edema) or biventricular failure
    • May progress to cardiogenic shock Cardiogenic shock Shock resulting from diminution of cardiac output in heart disease. Types of Shock due to a ↓ in cardiac output Cardiac output The volume of blood passing through the heart per unit of time. It is usually expressed as liters (volume) per minute so as not to be confused with stroke volume (volume per beat). Cardiac Mechanics
  • Mural thrombus Mural thrombus Myocardial Infarction formation with potential embolization Embolization A method of hemostasis utilizing various agents such as gelfoam, silastic, metal, glass, or plastic pellets, autologous clot, fat, and muscle as emboli. It has been used in the treatment of spinal cord and intracranial arteriovenous malformations, renal arteriovenous fistulas, gastrointestinal bleeding, epistaxis, hypersplenism, certain highly vascular tumors, traumatic rupture of blood vessels, and control of operative hemorrhage. Gastrointestinal Bleeding of the clot can lead to:
    • Limb ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage
    • Stroke
    • Mesenteric ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage
    • Renal infarction Renal Infarction Imaging of the Urinary System
• > 14 days post-MI:
  • Dressler (post-MI) syndrome:
    • Autoimmune sensitization to antigens released during cardiomyocyte death 
    • Presents with signs of pericarditis Pericarditis Pericarditis is an inflammation of the pericardium, often with fluid accumulation. It can be caused by infection (often viral), myocardial infarction, drugs, malignancies, metabolic disorders, autoimmune disorders, or trauma. Acute, subacute, and chronic forms exist. Pericarditis (e.g., pleuritic pain Pleuritic Pain Pneumothorax, friction rub, fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever) 
    • May result in elevation of troponins and leukocytosis Leukocytosis A transient increase in the number of leukocytes in a body fluid. West Nile Virus
    • ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) shows diffuse ST elevations
    • May have pericardial effusion Pericardial effusion Fluid accumulation within the pericardium. Serous effusions are associated with pericardial diseases. Hemopericardium is associated with trauma. Lipid-containing effusion (chylopericardium) results from leakage of thoracic duct. Severe cases can lead to cardiac tamponade. Pericardial Effusion and Cardiac Tamponade (abnormal amount of fluid in the pericardial cavity Pericardial cavity Heart: Anatomy of the heart) 
    • Can be complicated by cardiac tamponade Tamponade Pericardial effusion, usually of rapid onset, exceeding ventricular filling pressures and causing collapse of the heart with a markedly reduced cardiac output. Pericarditis/hemopericardium
  • Ventricular aneurysm Ventricular aneurysm A localized bulging or dilatation in the muscle wall of a heart (myocardium), usually in the left ventricle. Blood-filled aneurysms are dangerous because they may burst. Fibrous aneurysms interfere with the heart function through the loss of contractility. True aneurysm is bound by the vessel wall or cardiac wall. False aneurysms are hematoma caused by myocardial rupture. Myocardial Infarction presenting with:
    • Seen in totally occluded LAD 
    • Persistent ST elevations and T-wave inversions > 3 weeks post-MI
    • Signs of angina (e.g., dyspnea Dyspnea Dyspnea is the subjective sensation of breathing discomfort. Dyspnea is a normal manifestation of heavy physical or psychological exertion, but also may be caused by underlying conditions (both pulmonary and extrapulmonary). Dyspnea on exertion)
    • Systolic murmur and/or S3 S3 Heart Sounds/ S4 S4 Heart Sounds sounds

Differential Diagnosis

• Vasospastic angina Vasospastic Angina Vasospastic angina, also known as Prinzmetal or variant angina, is an uncommon cause of chest pain due to transient coronary artery spasms. The pathophysiology is distinguished from stable or unstable angina secondary to atherosclerotic coronary artery disease (CAD). Vasospastic Angina: uncommon cause of chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways due to transient coronary artery Coronary Artery Truncus Arteriosus spasms Spasms An involuntary contraction of a muscle or group of muscles. Spasms may involve skeletal muscle or smooth muscle. Ion Channel Myopathy. The clinical presentation of vasospastic angina Vasospastic Angina Vasospastic angina, also known as Prinzmetal or variant angina, is an uncommon cause of chest pain due to transient coronary artery spasms. The pathophysiology is distinguished from stable or unstable angina secondary to atherosclerotic coronary artery disease (CAD). Vasospastic Angina is characterized by spontaneous episodes of chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways due to a transient decrease in blood flow Blood flow Blood flow refers to the movement of a certain volume of blood through the vasculature over a given unit of time (e.g., mL per minute). Vascular Resistance, Flow, and Mean Arterial Pressure to the epicardial arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology. Diagnosis is made by clinical history, normal exam, and ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG). Cardiac enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body’s constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes and PCI are usually normal. Management includes the prevention of vasospasm with calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes channel blockers and the relief of angina with nitrates Nitrates Nitrates are a class of medications that cause systemic vasodilation (veins > arteries) by smooth muscle relaxation. Nitrates are primarily indicated for the treatment of angina, where preferential venodilation causes pooling of blood, decreased preload, and ultimately decreased myocardial O2 demand. Nitrates. 
• Aortic dissection Aortic dissection Aortic dissection occurs due to shearing stress from pulsatile pressure causing a tear in the tunica intima of the aortic wall. This tear allows blood to flow into the media, creating a “false lumen.” Aortic dissection is most commonly caused by uncontrolled hypertension. Aortic Dissection: due to shearing stress from pulsatile pressure causing a tear in the tunica intima Tunica intima The innermost layer of an artery or vein, made up of one layer of endothelial cells and supported by an internal elastic lamina. Arteries: Histology of the aortic wall, often associated with hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with aortic dissection Aortic dissection Aortic dissection occurs due to shearing stress from pulsatile pressure causing a tear in the tunica intima of the aortic wall. This tear allows blood to flow into the media, creating a “false lumen.” Aortic dissection is most commonly caused by uncontrolled hypertension. Aortic Dissection often present with acute, tearing chest or back pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways. Diagnosis is made by CT imaging. Type A dissections (in the ascending aorta Ascending aorta Mediastinum and Great Vessels: Anatomy) are a surgical emergency Surgical Emergency Acute Abdomen because of the risk of imminent rupture. Type B dissections (in the descending aorta Descending aorta Mediastinum and Great Vessels: Anatomy) can often be managed medically with beta-blockers Beta-blockers Drugs that bind to but do not activate beta-adrenergic receptors thereby blocking the actions of beta-adrenergic agonists. Adrenergic beta-antagonists are used for treatment of hypertension, cardiac arrhythmias, angina pectoris, glaucoma, migraine headaches, and anxiety. Class 2 Antiarrhythmic Drugs (Beta Blockers) and calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes channel blockers. 
• Pulmonary embolism Pulmonary Embolism Pulmonary embolism (PE) is a potentially fatal condition that occurs as a result of intraluminal obstruction of the main pulmonary artery or its branches. The causative factors include thrombi, air, amniotic fluid, and fat. In PE, gas exchange is impaired due to the decreased return of deoxygenated blood to the lungs. Pulmonary Embolism: presents with pleuritic pain Pleuritic Pain Pneumothorax, dyspnea Dyspnea Dyspnea is the subjective sensation of breathing discomfort. Dyspnea is a normal manifestation of heavy physical or psychological exertion, but also may be caused by underlying conditions (both pulmonary and extrapulmonary). Dyspnea, tachycardia Tachycardia Abnormally rapid heartbeat, usually with a heart rate above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia. Sepsis in Children, and occasionally chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways. Risk factors for pulmonary embolism Pulmonary Embolism Pulmonary embolism (PE) is a potentially fatal condition that occurs as a result of intraluminal obstruction of the main pulmonary artery or its branches. The causative factors include thrombi, air, amniotic fluid, and fat. In PE, gas exchange is impaired due to the decreased return of deoxygenated blood to the lungs. Pulmonary Embolism are prolonged immobilization Immobilization Delirium, oral contraceptives or estrogen therapy Estrogen therapy The use of hormonal agents with estrogen-like activity in postmenopausal or other estrogen-deficient women to alleviate effects of hormone deficiency, such as vasomotor symptoms, dyspareunia, and progressive development of osteoporosis. This may also include the use of progestational agents in combination therapy. Menopause, smoking Smoking Willful or deliberate act of inhaling and exhaling smoke from burning substances or agents held by hand. Interstitial Lung Diseases, and obesity Obesity Obesity is a condition associated with excess body weight, specifically with the deposition of excessive adipose tissue. Obesity is considered a global epidemic. Major influences come from the western diet and sedentary lifestyles, but the exact mechanisms likely include a mixture of genetic and environmental factors. Obesity. Diagnosis of venous thromboembolism Thromboembolism Obstruction of a blood vessel (embolism) by a blood clot (thrombus) in the blood stream. Systemic Lupus Erythematosus is made by CT. ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) may be normal or may show ST-segment changes. Management is urgent, with anticoagulation Anticoagulation Pulmonary Hypertension Drugs to prevent further propagation Propagation Propagation refers to how the electrical signal spreads to every myocyte in the heart. Cardiac Physiology of the clot.
• Pericarditis Pericarditis Pericarditis is an inflammation of the pericardium, often with fluid accumulation. It can be caused by infection (often viral), myocardial infarction, drugs, malignancies, metabolic disorders, autoimmune disorders, or trauma. Acute, subacute, and chronic forms exist. Pericarditis: inflammatory disorder of the pericardium Pericardium A conical fibroserous sac surrounding the heart and the roots of the great vessels (aorta; venae cavae; pulmonary artery). Pericardium consists of two sacs: the outer fibrous pericardium and the inner serous pericardium. The latter consists of an outer parietal layer facing the fibrous pericardium, and an inner visceral layer (epicardium) resting next to the heart, and a pericardial cavity between these two layers. Heart: Anatomy resulting in chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways that is usually constant and may manifest with diffuse ST-segment elevation on ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG). Etiologies can be infectious (usually viral), post-MI, due to medications, or due to malignancy Malignancy Hemothorax. Treatment is supportive if viral or with management of the underlying cause.
• Costochondritis: due to inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation of the cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage: Histology in the rib cage Rib cage The bony thoracic enclosure consisting of the vertebral column; the ribs; the sternum; and the costal cartilage. Chest Wall: Anatomy. Costochondritis presents with chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways that is reproducible on palpation Palpation Application of fingers with light pressure to the surface of the body to determine consistency of parts beneath in physical diagnosis; includes palpation for determining the outlines of organs. Dermatologic Examination. It may be due to trauma, strain, or viral infection. Diagnosis is made clinically and by the exclusion of coronary disease with appropriate testing. Treatment is with local measures and NSAIDs NSAIDS Primary vs Secondary Headaches.
• Esophageal spasm: painful contraction of the esophagus Esophagus The esophagus is a muscular tube-shaped organ of around 25 centimeters in length that connects the pharynx to the stomach. The organ extends from approximately the 6th cervical vertebra to the 11th thoracic vertebra and can be divided grossly into 3 parts: the cervical part, the thoracic part, and the abdominal part. Esophagus: Anatomy that can present with severe, intermittent chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways. Diagnosis is by ruling out cardiac causes of chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, esophageal manometry Manometry Measurement of the pressure or tension of liquids or gases with a manometer. Achalasia, and a barium swallow Barium Swallow Imaging of the Intestines study. Management may include antispasmodic Antispasmodic Antispasmodics are a group of medications used to reduce excessive GI smooth muscle contractility and spasm. These medications may be helpful in those with abdominal pain due to conditions such as irritable bowel syndrome, although their efficacy is controversial. Antispasmodics medications and, in some cases, surgery.
• Takotsubo cardiomyopathy Takotsubo Cardiomyopathy Takotsubo cardiomyopathy (also known as stress cardiomyopathy, or “broken heart syndrome”) is a type of non-ischemic cardiomyopathy in which there is transient regional systolic dysfunction of the left ventricle. Patients present with symptoms of acute coronary syndrome, including chest pressure and shortness of breath. Takotsubo Cardiomyopathy: type of nonischemic cardiomyopathy Cardiomyopathy Cardiomyopathy refers to a group of myocardial diseases associated with structural changes of the heart muscles (myocardium) and impaired systolic and/or diastolic function in the absence of other heart disorders (coronary artery disease, hypertension, valvular disease, and congenital heart disease). Cardiomyopathy: Overview and Types in which there is transient regional systolic dysfunction Systolic dysfunction Dilated Cardiomyopathy of the left ventricle. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship present with symptoms of acute coronary syndrome, including chest pressure and shortness of breath Shortness of breath Dyspnea is the subjective sensation of breathing discomfort. Dyspnea is a normal manifestation of heavy physical or psychological exertion, but also may be caused by underlying conditions (both pulmonary and extrapulmonary). Dyspnea. ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) may show ST-segment elevations. Coronary angiography Angiography Radiography of blood vessels after injection of a contrast medium. Cardiac Surgery will not show obstructed arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology. Echocardiography Echocardiography Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic. Tricuspid Valve Atresia (TVA) will demonstrate characteristic apical wall motion abnormalities. Treatment includes beta-blockers Beta-blockers Drugs that bind to but do not activate beta-adrenergic receptors thereby blocking the actions of beta-adrenergic agonists. Adrenergic beta-antagonists are used for treatment of hypertension, cardiac arrhythmias, angina pectoris, glaucoma, migraine headaches, and anxiety. Class 2 Antiarrhythmic Drugs (Beta Blockers) and the removal of inciting stressors.
• Myocarditis Myocarditis Myocarditis is an inflammatory disease of the myocardium, which may occur alone or in association with a systemic process. There are numerous etiologies of myocarditis, but all lead to inflammation and myocyte injury, most often leading to signs and symptoms of heart failure. Myocarditis: inflammatory disease of the myocardium Myocardium The muscle tissue of the heart. It is composed of striated, involuntary muscle cells connected to form the contractile pump to generate blood flow. Heart: Anatomy that can mimic an acute MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction, especially in younger patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship (< 45 years). It may occur alone or in association with a systemic process. There are numerous etiologies, but all lead to inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation and myocyte injury. The diagnosis is supported by clinical findings, laboratory evaluation, and cardiac imaging. Management is supportive and aimed at addressing complications.