Recurrent left ventricular mural thrombi in a patient with acute myocarditis

A case of acute myocarditis with recurrent left ventricular mural thrombi in a 59-year-old man is reported. Two-dimensional echocardiogram demonstrated left ventricular mural thrombus with apical dyskinesis on the 2nd day after the onset of chest oppression. No hemoagglutination abnormalities were present. Anticoagulation treatment with heparin was initiated. A two-dimensional echocardiogram obtained on the 15th day showed that the left ventricular wall motion had become normal and that the thrombus had disappeared. However, on the 38th day, a new pedunculated free mobile thrombus was found in the apical part of the left ventricle despite the normal wall motion. By the 46th day, the new thrombus had disappeared. The present case suggests that mural thrombi can occur in the absence of left ventricular dyskinesis and dilatation. Anticoagulation therapy resolved the mural thrombi but could not prevent the recurrence at the apex. Thus, in acute myocarditis, a mural thrombus may appear as a result of the endocardial damage, even when blood stasis is absent.