[A case of free-floating ball thrombus in left atrium with mitral stenosis].

We report a rare case of free-floating ball thrombus in the left atrium with mitral stenosis. The patient was 71-year-old woman who admitted to the local hospital for transient ischemic attack. Electrocardiography showed atrial fibrillation and an echocardiogram examination revealed free-floating ball thrombus in the left atrium with mitral stenosis. She was transferred to our hospital for emergency open heart operation. After removal of the ball thrombus, mitral valve replacement and modified MAZE procedure were successfully performed. The size of the ball thrombus was 40 x 30 x 33 mm and weighed 20 g. Postoperative course was uneventful.