Peripheral emboli from left ventricular thrombi of different echocardiographic appearance in acute myocardial infarction.

In four patients with anterior wall acute myocardial infarction (AMI) and left ventricular thrombi diagnosed by two-dimensional (2-D) echocardiography, disappearance of left ventricular thrombi was demonstrated by 2-D echocardiography immediately after the patients had suffered peripheral emboli. Two thrombi were pendulous with free motion during the cardiac contractions; one of these consisted of two separated pendulous clots that disappeared after two episodes of embolization six and 16 days, respectively, after the onset of AMI. Two thrombi were initially broad based, flat, and without intracavitary motion. One thrombus caused two episodes of peripheral emboli; the other began as a flat thrombus without intracavitary motion but progressed to show central echolucency and, then, vigorous intracavitary motion of the margin prior to embolization. Five of six embolic episodes occurred when these patients were receiving high-dose anticoagulants. These anticoagulants were administered once the thrombi were diagnosed. Left ventricular thrombi of very different appearance on 2-D echocardiography may cause embolization, which may occur during therapeutic anticoagulation administered after thrombi have developed in patients with AMI.