Roles of echocardiography and arrhythmia monitoring in the evaluation of patients with suspected systemic embolism.

Patients with suspected systemic embolism were evaluated for possible cardiac origin of emboli using echocardiography (280 patients) and prolonged arrhythmia (Holter) monitoring (150 patients). Echocardiography demonstrated cardiac abnormalities that might predispose to emboli in 47% of patients with and 14% of patients without clinically evident cardiovascular disease. Lesions that might be directly responsible for emboli, including thrombi, myxomas, and vegetations, were identified in only 11 patients (4%), all of whom had clinically evident disease. Patients less than 45 years of age with clinically evident cardiovascular disease were especially likely to have a potential source of embolism identified. Holter monitoring demonstrated atrial fibrillation in 15 patients. All 15, however, had known atrial fibrillation in the past or had atrial fibrillation detected on admission electrocardiogram, or both. The findings suggest that it is not cost effective to perform echocardiography and arrhythmia monitoring on all patients with suspected systemic emboli. Because echocardiographic identification of a likely responsible lesion was limited to those with clinically evident cardiovascular disease, a policy of performing this test only on such patients would have eliminated 38% of the echocardiographic studies in this series.