Prevalence of left atrial chamber and appendage thrombi in patients with atrial flutter and its clinical significance

OBJECTIVES The study was done to assess the prevalence of left atrial (LA) chamber and appendage thrombi in patients with atrial flutter (AFl) schedul ed for electrophysiologic study (EPS), to evaluate the prevalence of thromb oembolic complications after transesophageal echocardiographic (TEE)-guided restoration of sinus rhythm and to evaluate clinical risk factors for a th rombogenic milieu. BACKGROUND Recent studies showed controversial results on the prevalence of atrial thrombi and the risk of thromboembolism after restoring sinus rhyth m in patients with AFl. METHODS Between 1995 and 1999, patients with AR who were scheduled for EPS were included in the study. After transesophageal assessment of the left at rial appendage and exclusion of thrombi, an effective anticoagulation was i nitiated and patients underwent EPS within 24 h. RESULTS We performed 202 EPSs (radiofrequency catheter ablation, n = 122; o verdrive stimulation, n = 64; electrical cardioversion, n = 16) in 139 cons ecutive patients with AFl. Fifteen patients with a thrombogenic milieu were identified. All of them had paroxysmal atrial fibrillation (AF). Transesop hageal echocardiography revealed LA thrombi in two cases (1%). After EPS no thromboembolic complications were observed. Diabetes mellitus, arterial hy pertension and a decreased left ventricular ejection fraction were found to be independent risk factors associated with a thrombogenic milieu. CONCLUSIONS The findings of a low prevalence of LA appendage thrombi (1%) i n patients with AFl and a close correlation between a history of previous e mbolism and paroxysmal AF support the current guidelines that patients with pure AR do not require anticoagulation therapy, whereas patients with AFl and paroxysmal AF should receive anticoagulation therapy. In addition, the presence of clinical risk factors should alert the physician to an increase d likelihood for a thrombogenic milieu. (C) 2001 by the American College of Cardiology.