Viral Myocarditis

Excerpt

Myocarditis is an inflammatory heart muscle (myocardium) process with focal and diffuse involvement. Clinically, myocarditis can present as an acute, subacute, or chronic disease process. The presentation can be highly variable in symptomatic patients, from generalized fatigue, malaise, chest pain, congestive heart failure (CHF), cardiogenic shock, arrhythmias, and cardiac arrest.

In the United States and other developed countries, viral infections are most frequently the cause of myocarditis. In developing countries, rheumatic carditis, Chagas disease, and complications related to advanced HIV/AIDS are significant causes of myocarditis. Other causes include toxic myocarditis, related to drugs that may cause an insidious form of the disease. The exact incidence of myocarditis is unclear because of the above heterogenicity.

Myocarditis is diagnosed based on clinical presentation. Diagnosis is classically confirmed by endomyocardial biopsy via established histologic, immunologic, and immunohistochemical criteria.

Myocarditis can occur in an otherwise healthy person and quickly result in progressive heart failure. Myocarditis may be acute, lasting less than 2 weeks, or chronic, lasting more than 2 weeks.