Atrial fibrillation especially when long-lasting can cause complications which may endanger ones life, such as: systemic embolism, hypertrophy of cardiac chambers, contractility disturbances and heart insufficiency due to tachycardiomyopathy. This study presents a case report of two patients with atrial fibrillation not caused by a rheumatic disease. Case I presents a patient after two myocardial infarcts (MI) with atrial fibrillation of 18 months of duration, in whom we found a thrombus in the left atrial appendage during transesophageal echocardiography (TEE). Anticoagulation therapy resolved the thrombus in 6 weeks. Sinus rhythm was restored following electroconversion which improved left ventricular systolic hemodynamic parameters during a 6 months period of observations. Case II presents a patient with congestive cardiomyopathy, atrial fibrillation and a cerebral stroke in the past in whom we found 2 large thrombi during TEE which resolved following 12 weeks of anticoagulation therapy. Left ventricular systolic hemodynamic parameters returned to normal values(after 6 months) following TEE. In both cases we found no changes in end-diastolic left ventricular parameters. Following sinus rhythm restoration we noted a reduction in left atrial parameters.

Keywords: Atrial Fibrillation, left atrial appendage, thrombus, Tachycardiomyopathy