Myocarditis refers to inflammation, necrosis, or myocytolysis and may be caused by many infectious, connective tissue, granulomatous, toxic, or idiopathic processes affecting the myocardium with or without associated systemic manifestations of the disease process or involvement of the endocardium or pericardium.

Etiology:

The most common causative agents in children are adenovirus, coxsackievirus B, and other enteroviruses, although most known viral agents have been implicated.

Pathophysiology:

Acute viral myocarditis may produce a fulminant inflammatory process characterized by cellular infiltrates, cell degeneration and necrosis, and subsequent fibrosis. Viral myocarditis may also become a chronic process with persistence of viral RNA or DNA (but not infectious virus particles) in the myocardium.In addition, some viral proteins may share antigenic epitopes with host cells, which results in autoimmune damage to the antigenically related myocyte.

The net final result of chronic viral-associated inflammation is often dilated cardiomyopathy.

Clinical Manifestations:

Signs and symptoms depend on the patient’s age and the acute or chronic nature of the infection. A neonate may initially have fever, severe heart failure, respiratory distress, cyanosis, distant heart Continue reading »