An infant with dilated cardiomyopathy confirmed as myocarditis by endomyocardial biopsy.

A case of an 11-month-old infant who was incidentally diagnosed as having myocarditis by right and left ventricular endomyocardial biopsy is reported. This patient was admitted because of heart failure. Chest X-ray showed cardiomegaly and an electrocardiogram revealed decreased voltage with right atrial and right ventricular overloading. A dilated left ventricle with poor ejection fraction was shown in an echocardiogram. Dilated cardiomyopathy was the initial diagnosis since there was no episode of preceding viral infection or evidence of an inflammatory process in routine laboratory investigations. However, the biopsy findings, including massive infiltration of inflammatory cells and myocyte degeneration, indicated myocarditis. To our knowledge, this is the youngest patient in whom myocarditis has been confirmed by endomyocardial biopsy.