MYOCARDITIS

Inflammation of the myocardium that may progress to chronic dilated cardiomyopathy, most commonly due to acute viral infection (e.g., parvovirus B19, coxsackievirus, adenovirus, Epstein-Barr virus). Myocarditis may also develop in pts with HIV infection, hepatitis C or Lyme disease. Chagas’ disease is a common cause of myocarditis in endemic areas, typically Central and South America.



History 

Fever, fatigue, palpitations; if LV dysfunction develops, symptoms of heart failure are present. Viral myocarditis may be preceded by URI.

Physical Examination 

Fever, tachycardia, soft S1; S3 common.

Laboratory 

CK-MB isoenzyme and cardiac troponins may be elevated in absence of MI. Convalescent antiviral antibody titers may rise. ECG Transient ST-T-wave abnormalities.

CXR 

Cardiomegaly

Echocardiogram, Cardiac MRI 

Depressed LV function; pericardial effusion present if accompanying pericarditis present. MRI demonstrates mid-wall gadolinium enhancement.

Myocarditis TREATMENT 

Rest; treat as heart failure ; efficacy of immunosuppressive therapy (e.g., steroids) has not been demonstrated except in isolated conditions such as sarcoidosis and giant cell myocarditis. In fulminant cases, cardiac transplantation may be indicated.