[A case of left atrial ball thrombus].

A 76-year-old man admitted to one hospital complaining of transient left hemiparesis. Because of arrhythmia, he was examined by an echocardiogram and found to have an oval free-floating thrombus in his left atrium concomitant with mitral stenosis. He was transferred to our hospital for emergency surgery. On operation, a 3 x 4 cm ball thrombus was removed and diseased mitral valve was replaced with a SJM prosthetic valve. His postoperative course was relatively uneventful. Though left atrial ball thrombus is rarely found among the patients with mitral valve disease, when left atrial ball thrombus is found, immediate surgical intervention is recommended to avoid sudden death.