[Two cases of mitral stenosis associated with ball thrombus in the left atrium].

Two patients (55-year-old female and 77-year-old female) were operated on for mitral stenosis associated with left atrial ball thrombus. The first case had the episode of cerebral infarction and second case had syncopal attack. Both of them presented with systemic arterial embolism. After confirmation of the diagnosis by echocardiography, removal of ball thrombi, OMC and MVR were carried out urgently. Considering high risk of "hole in one sudden death" and multiple-episodes of systemic embolization, ball thrombus should be removed as urgent following confirmation of diagnosis.