Two cases of congestive cardiomyopathy were proved to be due to chronic atrial automatic-focus tachycardia. Surgical elimination of the tachycardia resulted in normalization of cardiac function in both cases. We suggest that patients with congestive cardiomyopathy be carefully screened for supraventricular tachycardia. Patients with chronic supraventricular tachycardia should be treated aggressively to prevent myocardial dysfunction.
