[Giant Left Atrium Thrombus after Left Atrial Appendectomy:Report of a Case].

A 78-years-old woman was admitted to our hospital due to recurrence of cerebral infarction. She had history of chronic atrial fibrillation, so we performed left atrium appendectomy for prevention of cardiogenic brain embolism. But a giant left atrium thrombus appeared in spite of left atrial appendage closure and anticoagulant therapy. Echo cardiogram showed severe spontaneous echo contrast in the large left atrium. The criteria of mitral valve stenosis were not met, but restriction of the mitral valve opening was suspected. So, we performed removal of left atrium thrombus and mitral valve replacement. The left atrium thrombus did not attach at the stump of the left atrial appendage, but at the junction of left pulmonary vein and left atrium. She was transferred without recurrence of left atrium thrombus. Severe left atrial blood stasis may cause thrombus in spite of left atrium appendectomy.