Myocarditis is an 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, which may occur alone or in association with a systemic process. There are numerous etiologies of myocarditis, 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, most often leading to signs and symptoms 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). The course of myocarditis may vary based on the etiology and timeline of symptom progression. The diagnosis is supported by clinical findings, laboratory evaluation, and cardiac imaging. A definitive diagnosis by endomyocardial biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma is rarely required. Management is supportive and aimed at addressing complications.
Last updated: 14 Jun, 2022
Myocarditis is an 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.
The following table summarizes the infectious Infectious Febrile Infant causes of myocarditis. Keep in mind that this list is not exhaustive.
Viral | Bacterial | Parasitic | Fungal |
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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 due to various etiologies leads to enlargement of the heart and dilation of all chambers.
The clinical presentation can vary based on the severity and temporal progression of symptoms. Most signs and symptoms are related 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).
Myocarditis is classified based on temporal progression.
Laboratory studies:
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):
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:
Echocardiogram Echocardiogram Transposition of the Great Vessels:
Transthoracic
echocardiogram
Echocardiogram
Transposition of the Great Vessels images for a patient with myocarditis:
(A) Long
axis
Axis
The second cervical vertebra.
Vertebral Column: Anatomy view and (B) short
axis
Axis
The second cervical vertebra.
Vertebral Column: Anatomy view demonstrating a
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 (marked in blue)
Cardiac MRI Cardiac MRI Imaging of the Heart and Great Vessels:
Cardiac MRI Cardiac MRI Imaging of the Heart and Great Vessels suggestive of myocarditis. White arrows mark enhancement 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, which is suggestive of 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
Image: “Myocarditis in Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship With Antisynthetase Syndrome Antisynthetase Syndrome Dermatomyositis: 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, Presentation, and Outcomes” by Dieval, C. et al AL Amyloidosis. License: CC BY 4.0Cardiac MRI Cardiac MRI Imaging of the Heart and Great Vessels demonstrating mid-wall gadolinium Gadolinium An element of the rare earth family of metals. It has the atomic symbol gd, atomic number 64, and atomic weight 157. 25. Its oxide is used in the control rods of some nuclear reactors. Magnetic Resonance Imaging (MRI) enhancement of the lateral wall, which is a characteristic finding
Image: “ Myopericarditis Myopericarditis Coxsackievirus complicated by 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 in an immunocompetent patient with acute cytomegalovirus Cytomegalovirus CMV is a ubiquitous double-stranded DNA virus belonging to the Herpesviridae family. CMV infections can be transmitted in bodily fluids, such as blood, saliva, urine, semen, and breast milk. The initial infection is usually asymptomatic in the immunocompetent host, or it can present with symptoms of mononucleosis. Cytomegalovirus infection: A case report” by Vandamme, Y.M. et al AL Amyloidosis. License: CC BY 2.0Endomyocardial biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma is the gold standard for diagnosis; however, it is rarely needed.
Indications:
Findings:
Endomyocardial
biopsy
Biopsy
Removal and pathologic examination of specimens from the living body.
Ewing Sarcoma in eosinophilic myocarditis:
There is infiltration of
eosinophils
Eosinophils
Granular leukocytes with a nucleus that usually has two lobes connected by a slender thread of chromatin, and cytoplasm containing coarse, round granules that are uniform in size and stainable by eosin.
Innate Immunity: Phagocytes and Antigen Presentation (arrows) seen on hematoxylin and eosin staining.
Acute myocarditis due to
Plasmodium
Plasmodium
A genus of protozoa that comprise the malaria parasites of mammals. Four species infect humans (although occasional infections with primate malarias may occur). These are plasmodium falciparum; plasmodium malariae; plasmodium ovale, and plasmodium vivax. Species causing infection in vertebrates other than man include: plasmodium berghei; plasmodium chabaudi; p. Vinckei, and plasmodium yoelii in rodents; p. Brasilianum, plasmodium cynomolgi; and plasmodium knowlesi in monkeys; and plasmodium gallinaceum in chickens.
Antimalarial Drugs falciparum:
There is extensive lymphocytic infiltration.
Management for myocarditis is generally supportive, but often includes:
Medical therapy 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):
For fulminant 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):
Most patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship will have a partial or full recovery. However, long-term follow-up and monitoring are recommended.