Assessment of Cardioversion Using Transesophageal Echocardiography II (ACUTE II)

SPECIFIC AIM: To test the safety and feasibility of using low molecular weight heparin (LMWH, enoxaparin sodium; Lovenox, Sanofi-Aventis) in lieu of unfractionated heparin (UFH) as antithrombotic therapy for patients in atrial fibrillation undergoing transesophageal echocardiography (TEE) guided chemical or electrical cardioversion to sinus rhythm. HYPOTHESIS: Early cardioversion from atrial fibrillation can be safely performed using a short-term anticoagulation strategy of low molecular weight heparin (Lovenox, Sanofi-Aventis) compared to unfractionated heparin, accompanied by a TEE examination prior to cardioversion. The use of LMWH with TEE will result in a safe, cost-effective, and possible efficacious approach to cardioversion of atrial fibrillation compared to UFH with TEE.