Antithrombotic therapy in left ventricular thrombosis and systemic embolism.

Left ventricular (LV) thrombi are responsible for significant morbidity and mortality in our society. Twenty-five percent of cardiogenic emboli are associated with acute and chronic myocardial infarction. With the development of noninvasive imaging techniques LV thrombi have been increasingly recognized as an important clinical entity; the imaging method of choice is two-dimensional echocardiography. LV mural thrombi occur in one third of Q wave anterior myocardial infarctions; their occurrence in patients with non-Q wave infarction and inferior Q wave myocardial infarction is less than 5%. More than half of all LV thrombi are formed within 48 hours of acute myocardial infarction, and nearly all thrombi have been formed within a week of infarction. The development of an LV thrombus is associated with some risk of systemic embolization. To prevent LV thrombosis and systemic embolism, full-dose heparin followed by warfarin therapy for at least 3 months is indicated for patients with large anterior infarctions and those with heart failure. The use of thrombolytic therapy does not reduce the risk of LV thrombus formation; few data exist on whether early coronary angioplasty reduces the risk of LV thrombus formation and the risk of embolization. The proper treatment for patients with chronic LV thrombi remains unknown.