Cardioversion related thromboembolism: value of transesophageal echocardiography to guide cardioversion in patients with atrial fibrillation.

The aim of this article is to review two recent investigations of the value of transesophageal echocardiography to guide direct current cardioversion in different patient populations. In the Ludwigshafener Observational Cardioversion Study (LOCS) a TEE was performed prior to electrical cardioversion in patients with atrial fibrillation who had been receiving oral anticoagulation adjusted to an international normalized ratio of 2 to 3 for at least three weeks. In contrast, the ACUTE study investigated the value of transesophageal echocardiography in patients with atrial fibrillation in whom long-term oral anticoagulants had not been initiated in comparison to standard anticoagulation therapy. Furthermore, the following questions in respect to anticoagulation therapy are addressed: (1) how should patients be approached for pharmacological or spontaneous conversion; (2) how to treat emergency situations, (3) what is the importance of the postcardioversion period and long-term anticoagulation therapy; and (4) what is the role of low molecular weight heparin in the pericardioversion period.