What is myocarditis?

Myocarditis is inflammation or degeneration of the heart muscle. Myocarditis may be a complication during or after various viral, bacterial, or parasitic infectious diseases, such as polio, influenza, rubella, or rheumatic fever. Myocarditis is often caused by various diseases such as syphilis, goiter, endocarditis, or hypertension, however, myocarditis may appear as a primary disease in adults or as a degenerative disease of old age.
Myocarditis may be associated with dilation (enlargement due to weakness of the heart muscle) or with hypertrophy (overgrowth of the muscle tissue). Individuals who smoke cigarettes have a higher mortality and risk of myocardial infarction than individuals who do not smoke.
In some cases of myocarditis may progress to congestive heart failure, requiring hospitalization, heart failure medications, or cardiac transplantation.

Cause of Myocarditis


Myocarditis is a caused by inflammation of the muscle of the heart. Although a variety of medical conditions can cause myocarditis, the most common cause is infection by viruses. Enteroviruses are recognized as the most common cause of myocarditis. Over many years, a chronic enterovirus heart infection and the body’s response to that infection in the heart can lead to irreversible heart muscle damage and heart failure.

Frequency

In United States

Frequency is difficult to ascertain, owing to the wide variation of clinical presentation. Incidence is usually estimated at 1-10 cases per 100,000 persons. Incidence of positive right ventricular biopsy findings in patients with suspected myocarditis is highly variable (ranging from 0-80%). According to estimates, as many as 1-5% of patients with acute viral infections may have involvement of the myocardium.