Electrical cardioversion and thrombogenesis. Apropos a case

: We report a case of a 73-years-old patient with atrial fibrillation who underwent direct current cardioversion. The transesophageal echocardiography performed before cardioversion excluded the presence of atrial thrombus. After cardioversion a new transesophageal echocardiography detected a thrombus in the left atrial appendage despite oral anticoagulation. Mechanism of thrombus formation and the need for oral anticoagulation before the procedure is being discussed.