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Dilated Cardiomyopathy

Dilated 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 (DCM) is the most common type of non-ischemic 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 and a common cause 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) (HF). The cause may be idiopathic Idiopathic Dermatomyositis, familial, or secondary to a variety of underlying conditions. The disease is characterized by the enlargement of 1 or both ventricles and reduced systolic function. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship typically present with symptoms of HF such as 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, 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, weakness, and peripheral edema Peripheral edema Peripheral edema is the swelling of the lower extremities, namely, legs, feet, and ankles. Edema. Blood tests, 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), X-rays X-rays X-rays are high-energy particles of electromagnetic radiation used in the medical field for the generation of anatomical images. X-rays are projected through the body of a patient and onto a film, and this technique is called conventional or projectional radiography. X-rays, 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), and other cardiac studies and procedures are typically done to obtain the diagnosis. Treatment includes medications used to reduce volume overload (e.g., diuretics Diuretics Agents that promote the excretion of urine through their effects on kidney function. Heart Failure and Angina Medication) and manage HF (e.g., 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)). Devices such as pacemakers and cardioverter-defibrillators may also be needed. In severe cases, a heart transplant is required. Complications include thromboembolic events and sudden cardiac death Sudden cardiac death 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.

Last updated: Jun 26, 2023

Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

Overview

Definition

Dilated 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 (DCM) is a disease of the cardiac muscle Cardiac muscle The muscle tissue of the heart. It is composed of striated, involuntary muscle cells connected to form the contractile pump to generate blood flow. Muscle Tissue: Histology:

  • Associated with electrical and mechanical dysfunction causing impaired systolic function
  • Featuring the dilatation of 1 or both ventricles
  • Not explained by 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, valvular disease, or coronary artery Coronary Artery Truncus Arteriosus disease

Epidemiology

  • Most common type of non-ischemic 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
  • Annual 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: 6 per 100,000
  • 10,000 deaths and 46,000 hospitalizations yearly in the United States
  • Affects men > women
  • Occurs in all ages, most common in those 20–60 years old
  • Most common indication for heart transplant

Etiology

  • Idiopathic Idiopathic Dermatomyositis in approximately 50% of cases 
  • Familial DCM:
    • Caused by a multitude of gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics mutations
    • 20%–35% of cases initially diagnosed as idiopathic Idiopathic Dermatomyositis are later found to have a familial component after additional family screening Screening Preoperative Care.
    • Typical inheritance pattern is autosomal dominant Autosomal dominant Autosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal dominant diseases are expressed when only 1 copy of the dominant allele is inherited. Autosomal Recessive and Autosomal Dominant Inheritance; however, all inheritance patterns have occurred.
  • Arrhythmias (particularly those that cause sustained 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, e.g., 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)
  • Infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease:
    • Viral infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease causing 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 (e.g., coxsackievirus Coxsackievirus Coxsackievirus is a member of a family of viruses called Picornaviridae and the genus Enterovirus. Coxsackieviruses are single-stranded, positive-sense RNA viruses, and are divided into coxsackie group A and B viruses. Both groups of viruses cause upper respiratory infections, rashes, aseptic meningitis, or encephalitis. Coxsackievirus, influenza Influenza Influenza viruses are members of the Orthomyxoviridae family and the causative organisms of influenza, a highly contagious febrile respiratory disease. There are 3 primary influenza viruses (A, B, and C) and various subtypes, which are classified based on their virulent surface antigens, hemagglutinin (HA) and neuraminidase (NA). Influenza typically presents with a fever, myalgia, headache, and symptoms of an upper respiratory infection. Influenza Viruses/Influenza, or HIV HIV Anti-HIV Drugs)
    • Chagas disease Chagas disease Infection with the protozoan parasite trypanosoma cruzi, a form of trypanosomiasis endemic in central and south america. It is named after the brazilian physician carlos chagas, who discovered the parasite. Infection by the parasite (positive serologic result only) is distinguished from the clinical manifestations that develop years later, such as destruction of parasympathetic ganglia; chagas cardiomyopathy; and dysfunction of the esophagus or colon. Trypanosoma cruzi/Chagas disease (protozoan infection due to Trypanosoma cruzi Trypanosoma cruzi Chagas disease is an infection caused by the American trypanosome Trypanosoma cruzi. This parasitic protozoan is transmitted in the feces of reduviid bugs in South and Central America. Acute infection may present with inflammation at the inoculation site (chagoma), fever, and lymphadenopathy. Untreated, chronic infection can progress to severe complications. Trypanosoma cruzi/Chagas disease)
  • Endocrine disorders (e.g., hyperthyroidism Hyperthyroidism Hypersecretion of thyroid hormones from the thyroid gland. Elevated levels of thyroid hormones increase basal metabolic rate. Thyrotoxicosis and Hyperthyroidism or 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)
  • Autoimmune or inflammatory conditions (e.g., lupus or sarcoidosis Sarcoidosis Sarcoidosis is a multisystem inflammatory disease that causes noncaseating granulomas. The exact etiology is unknown. Sarcoidosis usually affects the lungs and thoracic lymph nodes, but it can also affect almost every system in the body, including the skin, heart, and eyes, most commonly. Sarcoidosis)
  • Neuromuscular genetic conditions (e.g., Duchenne muscular dystrophy Muscular Dystrophy Becker Muscular Dystrophy or Friedreich’s ataxia Ataxia Impairment of the ability to perform smoothly coordinated voluntary movements. This condition may affect the limbs, trunk, eyes, pharynx, larynx, and other structures. Ataxia may result from impaired sensory or motor function. Sensory ataxia may result from posterior column injury or peripheral nerve diseases. Motor ataxia may be associated with cerebellar diseases; cerebral cortex diseases; thalamic diseases; basal ganglia diseases; injury to the red nucleus; and other conditions. Ataxia-telangiectasia)
  • Deposition diseases (e.g., hemochromatosis Hemochromatosis A disorder of iron metabolism characterized by a triad of hemosiderosis; liver cirrhosis; and diabetes mellitus. It is caused by massive iron deposits in parenchymal cells that may develop after a prolonged increase of iron absorption. Hereditary Hemochromatosis or amyloidosis Amyloidosis Amyloidosis is a disease caused by abnormal extracellular tissue deposition of fibrils composed of various misfolded low-molecular-weight protein subunits. These proteins are frequently byproducts of other pathological processes (e.g., multiple myeloma). Amyloidosis)
  • Medications that cause cardiotoxicity:
    • Chemotherapeutic medications (classically an anthracycline, e.g., doxorubicin, or a monoclonal antibody, e.g., trastuzumab Trastuzumab A humanized monoclonal antibody against the ErbB-2 receptor (HER2). As an antineoplastic agent, it is used to treat breast cancer where HER2 is overexpressed. Targeted and Other Nontraditional Antineoplastic Therapy)
    • Antiretrovirals (most classically azidothymidine Azidothymidine Anti-HIV Drugs; also known as zidovudine Zidovudine A dideoxynucleoside compound in which the 3′-hydroxy group on the sugar moiety has been replaced by an azido group. This modification prevents the formation of phosphodiester linkages which are needed for the completion of nucleic acid chains. The compound is a potent inhibitor of HIV replication, acting as a chain-terminator of viral DNA during reverse transcription. It improves immunologic function, partially reverses the HIV-induced neurological dysfunction, and improves certain other clinical abnormalities associated with aids. Its principal toxic effect is dose-dependent suppression of bone marrow, resulting in anemia and leukopenia. Anti-HIV Drugs)
    • Hydroxychloroquine Hydroxychloroquine A chemotherapeutic agent that acts against erythrocytic forms of malarial parasites. Hydroxychloroquine appears to concentrate in food vacuoles of affected protozoa. It inhibits plasmodial heme polymerase. Immunosuppressants 
  • 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 treatment (particularly to the chest)
  • Peripartum 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:
    • Secondary to hemodynamic changes associated with 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
    • Occurs in the last month of 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 or the 1st months after giving birth 
  • Toxins:
    • Alcohol use disorder Alcohol use disorder Alcohol is one of the most commonly used addictive substances in the world. Alcohol use disorder (AUD) is defined as pathologic consumption of alcohol leading to impaired daily functioning. Acute alcohol intoxication presents with impairment in speech and motor functions and can be managed in most cases with supportive care. Alcohol Use Disorder
    • 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 and other illicit drug use
    • Exposure to heavy metals (e.g., cobalt, arsenic Arsenic A shiny gray element with atomic symbol as, atomic number 33, and atomic weight 75. It occurs throughout the universe, mostly in the form of metallic arsenides. Most forms are toxic. According to the fourth annual report on carcinogens, arsenic and certain arsenic compounds have been listed as known carcinogens. Metal Poisoning (Lead, Arsenic, Iron), mercury Mercury A silver metallic element that exists as a liquid at room temperature. It has the atomic symbol Hg (from hydrargyrum, liquid silver), atomic number 80, and atomic weight 200. 59. Mercury is used in many industrial applications and its salts have been employed therapeutically as purgatives, antisyphilitics, disinfectants, and astringents. It can be absorbed through the skin and mucous membranes which leads to mercury poisoning. Because of its toxicity, the clinical use of mercury and mercurials is diminishing. Renal Tubular Acidosis, or lead)
  • Nutritional deficiencies (e.g., thiamine Thiamine Also known as thiamine or thiamin, it is a vitamin C12H17N4OSCl of the vitamin B complex that is essential to normal metabolism and nerve function and is widespread in plants and animals Water-soluble Vitamins and their Deficiencies, selenium Selenium An element with the atomic symbol se, atomic number 34, and atomic weight 78. 97. It is an essential micronutrient for mammals and other animals but is toxic in large amounts. Selenium protects intracellular structures against oxidative damage. It is an essential component of glutathione peroxidase. Trace Elements, or carnitine Carnitine A constituent of striated muscle and liver. It is an amino acid derivative and an essential cofactor for fatty acid metabolism. Fatty Acid Metabolism)

Pathophysiology

  • Ventricular dilation caused by:
    • Left ventricle (LV) failure
    • Primary injury of heart muscle 
  • Ventricular dilatation leads to:
    • Thinning of heart muscle wall 
    • Weakening and enlargement of heart
    • Systolic failure:
      • Cardiac muscle Cardiac muscle The muscle tissue of the heart. It is composed of striated, involuntary muscle cells connected to form the contractile pump to generate blood flow. Muscle Tissue: Histology does not contract efficiently when deformed.
      • 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 decreases.
    • Diastolic failure: valvular insufficiency due to distortion Distortion Defense Mechanisms of cardiac architecture 
    • 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) (HF)

Clinical Presentation

Symptoms may develop and progress slowly over time, or develop abruptly. Symptoms are similar to those seen with HF.

Symptoms

  • 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/ 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 (especially with exertion)
  • Orthopnea Orthopnea Pulmonary Edema ( 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 when lying down)
  • Edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema of lower extremities and abdomen
  • Weight gain
  • 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)
  • Syncopal episodes
  • Chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
  • Palpitations Palpitations Ebstein’s Anomaly
  • 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 
  • Weakness

Physical exam findings

  • Cardiac:
  • Abdominal: ascites Ascites Ascites is the pathologic accumulation of fluid within the peritoneal cavity that occurs due to an osmotic and/or hydrostatic pressure imbalance secondary to portal hypertension (cirrhosis, heart failure) or non-portal hypertension (hypoalbuminemia, malignancy, infection). Ascites
  • Pulmonary:
    • Rales Rales Respiratory Syncytial Virus or crackles over lung fields (secondary to 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)
    • Respiratory distress
    • Low oxygen saturation Oxygen Saturation Basic Procedures
  • Vascular: jugular venous distention
  • Extremity:
    • Pitting edema Pitting edema Edema caused by excess fluid without excess colloid. Leaves “pits” due to fluid displacement when pressure is applied to the area Edema in lower extremities
    • Signs of venous stasis with discoloration in lower extremities

Diagnosis

Diagnosis is primarily through history and physical examination, laboratory examination, 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 imaging (confirmatory or to exclude other etiologies).

Laboratory studies

  • 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: marker 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) (↑)
  • Troponin: marker for 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 (↑)
  • CK-MB: another marker for 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 1st 24 hours, then returns to normal by 48–72 hours)
  • 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 sinus 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, left atrial enlargement, ventricular arrhythmias, or 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

Imaging

  • 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: may show enlarged heart and effusions (accumulation of fluid)
  • 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):
    • Assess:
      • Cardiac size
      • Structure
      • Function
      • Differentiates other forms of 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
    • Shows:
      • Enlarged ventricular diameter (dilation)
      • Normal or decreased wall thickness
      • Decreased inward endocardial systolic motion
      • Reduced left ventricular ejection fraction Ejection fraction Cardiac Cycle (LVEF)
    • Evidence of dilation of 1 or both ventricles and reduced systolic dysfunction necessary for diagnosis of dilated 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
  • Cardiac MRI Cardiac MRI Imaging of the Heart and Great Vessels: helps determine extent of myocardial damage and fibrosis Fibrosis Any pathological condition where fibrous connective tissue invades any organ, usually as a consequence of inflammation or other injury. Bronchiolitis Obliterans
  • Coronary angiography Angiography Radiography of blood vessels after injection of a contrast medium. Cardiac Surgery:
    • Helps rule out CAD
    • May show dilated, hypokinetic LV, normal coronary 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, and some degree of mitral regurgitation Regurgitation Gastroesophageal Reflux Disease (GERD)
  • Endomyocardial biopsy Endomyocardial biopsy Myocarditis with histologic examination:
    • Done in select cases:
      • Uncertain cause 
      • New-onset HF with associated hemodynamic compromise, ventricular arrhythmias, Mobitz type II atrioventricular (AV) block, 3rd-degree AV block AV block Atrioventricular (AV) block is a bradyarrhythmia caused by delay, or interruption, in the electrical conduction between the atria and the ventricles. Atrioventricular block occurs due to either anatomic or functional impairment, and is classified into 3 types. Atrioventricular block (AV block), or HF refractory to typical treatments
  • Obtain comprehensive family history Family History Adult Health Maintenance and genetic testing Genetic Testing Detection of a mutation; genotype; karyotype; or specific alleles associated with genetic traits, heritable diseases, or predisposition to a disease, or that may lead to the disease in descendants. It includes prenatal genetic testing. Myotonic Dystrophies if familial DCM suspected.

Management

Treatment

  • Medications:
  • Oral anticoagulation Anticoagulation Pulmonary Hypertension Drugs ( vitamin K Vitamin K A lipid cofactor that is required for normal blood clotting. Several forms of vitamin K have been identified: vitamin K 1 (phytomenadione) derived from plants, vitamin K 2 (menaquinone) from bacteria, and synthetic naphthoquinone provitamins, vitamin K 3 (menadione). Vitamin k 3 provitamins, after being alkylated in vivo, exhibit the antifibrinolytic activity of vitamin k. Green leafy vegetables, liver, cheese, butter, and egg yolk are good sources of vitamin k. Fat-soluble Vitamins and their Deficiencies antagonists, e.g., warfarin Warfarin An anticoagulant that acts by inhibiting the synthesis of vitamin K-dependent coagulation factors. Warfarin is indicated for the prophylaxis and/or treatment of venous thrombosis and its extension, pulmonary embolism, and atrial fibrillation with embolization. It is also used as an adjunct in the prophylaxis of systemic embolism after myocardial infarction. Warfarin is also used as a rodenticide. Anticoagulants) if LVEF < 35%
  • Device therapies (e.g., pacemaker Pacemaker A device designed to stimulate, by electric impulses, contraction of the heart muscles. It may be temporary (external) or permanent (internal or internal-external). Bradyarrhythmias or implanted cardioverter-defibrillator) if:
    • LVEF < 35%
    • Arrhythmias or other conduction disorders
    • LVEF > 35% with family history Family History Adult Health Maintenance of sudden cardiac death Sudden cardiac death 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 gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics mutations (e.g., LMNA) associated with a high risk for sudden cardiac death Sudden cardiac death 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
    • Syndromic diseases (e.g., muscular dystrophy Muscular Dystrophy Becker Muscular Dystrophy)
  • Heart transplant warranted in severe cases

Complications

  • Arrhythmias
  • Thromboembolic events (e.g., 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 or cerebrovascular accident Cerebrovascular accident 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)
  • Sudden cardiac death Sudden cardiac death 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

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

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 generally poor for individuals with this condition. 

Differential Diagnosis

  • Restrictive cardiomyopathy Restrictive Cardiomyopathy Restrictive cardiomyopathy (RCM) is a fairly uncommon condition characterized by progressive stiffening of the cardiac muscle, which causes impaired relaxation and refilling of the heart during diastole, resulting in diastolic dysfunction and eventual heart failure. Restrictive Cardiomyopathy: a condition secondary to scarring Scarring Inflammation and/or infiltration of the heart muscle ( amyloidosis Amyloidosis Amyloidosis is a disease caused by abnormal extracellular tissue deposition of fibrils composed of various misfolded low-molecular-weight protein subunits. These proteins are frequently byproducts of other pathological processes (e.g., multiple myeloma). Amyloidosis most common cause) characterized by a stiffening of the ventricles resulting in diastolic dysfunction Diastolic dysfunction Restrictive Cardiomyopathy and eventual HF. Presentation includes signs and symptoms of HF. Similar studies as DCM are used to help determine the diagnosis. Treatment is also similar, including medications and implantable devices such as pacemakers and cardioverter-defibrillators. A heart transplant may be needed when symptoms become severe and no longer responsive to treatments. 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 and survival are worse than with DCM. 
  • Hypertrophic cardiomyopathy Hypertrophic Cardiomyopathy Hypertrophic cardiomyopathy (HCM) is the most commonly inherited cardiomyopathy, which is characterized by an asymmetric increase in thickness (hypertrophy) of the left ventricular wall, diastolic dysfunction, and often left ventricular outflow tract obstruction. Hypertrophic Cardiomyopathy ( HCM HCM Hypertrophic cardiomyopathy (HCM) is the most commonly inherited cardiomyopathy, which is characterized by an asymmetric increase in thickness (hypertrophy) of the left ventricular wall, diastolic dysfunction, and often left ventricular outflow tract obstruction. Hypertrophic Cardiomyopathy): Gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics mutations affect the contractile components of the heart (sarcomeres) resulting in LV asymmetrical wall thickening, diastolic dysfunction Diastolic dysfunction Restrictive Cardiomyopathy, and LV outflow tract obstruction. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship may be asymptomatic or suffer sudden cardiac death Sudden cardiac death 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 as the 1st sign of disease. Symptomatic individuals have 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, chest pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, presyncope Presyncope Syncope, or 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. Diagnosis is made via 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), echocardiogram Echocardiogram Transposition of the Great Vessels, stress test, and cardiac MRI Cardiac MRI Imaging of the Heart and Great Vessels. Treatment involves 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) as 1st-line therapy with additional management depending on the presence of arrhythmias and LV outflow tract obstruction. 
  • 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: a type of non-ischemic 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 occurring due to extreme psychological or physical stress; also known as stress-induced 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 or “ broken heart syndrome Broken heart syndrome 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.” 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 is characterized by transient, regional systolic dysfunction of the LV. 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, and an 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 elevation. Coronary angiography Angiography Radiography of blood vessels after injection of a contrast medium. Cardiac Surgery can help to differentiate this condition from 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. An echocardiogram Echocardiogram Transposition of the Great Vessels can confirm the diagnosis by demonstrating characteristic apical wall motion abnormalities. Treatment includes the removal of inciting stressors and 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).

References

  1. (2021). Dilated Cardiomyopathy. Medline Plus. Retrieved February 3, 2021, from https://medlineplus.gov/ency/article/000168.htm
  2. Schaufelberger M. (2019). Cardiomyopathy and pregnancy. Heart. 105:1543-1551. Retrieved February 3, 2021, from https://heart.bmj.com/content/105/20/1543.info
  3. Weigner, M. & Morgan, J. P. (2019). Causes of dilated cardiomyopathy. UpToDate. Retrieved February 4, 2021, from https://www.uptodate.com/contents/causes-of-dilated-cardiomyopathy
  4. Cooper, L.T. (2019). Definition and classification of the cardiomyopathies. UpToDate. Retrieved February 4, 2021, from https://www.uptodate.com/contents/definition-and-classification-of-the-cardiomyopathies
  5. Hershberger, R.E. (2020). Familial dilated cardiomyopathy: Prevalence, diagnosis, and treatment. UpToDate. Retrieved February 4, 2021, from https://www.uptodate.com/contents/familial-dilated-cardiomyopathy-prevalence-diagnosis-and-treatment

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