Transient myocardial thickening in acute myocarditis--serial study by two-dimensional echocardiography.

A 13-year-old girl developed viral myocarditis complicated by pulmonary thromboembolism. Marked dilatation and reduction in the contractility of the left ventricle were noted in a two-dimensional echocardiogram on admission. The thicknesses of the left ventricle and the interventricular septum were both 8 mm at this time, but increased after the 9th day of the illness to reach 2 cm by the 15th day, with a concomitant reduction in the left ventricular cavity. The myocardial thickening gradually decreased and the ejection fraction improved on serial echocardiographic evaluations, and the wall thickness and ejection fraction returned to normal by the 32nd day. The myocarditis resolved without sequelae. The implications of this transient myocardial thickening are discussed.