[A case of true aneurysm of the mitral valve associated with torn chordae]

The patient was a 62 year old woman complaining of severe exertional dyspnea. Preoperative echocardiogram demonstrated the abnormal uniform echo of the anterior leaflet of the mitral valve which protruded toward the left atrium in systole as well as in diastole. Severe mitral regurgitation was also detected. The aneurysm of the anterior leaflet of the mitral valve was confirmed during the operation and mitral valve replacement was performed. The postoperative course was uneventful. Pathological examination of the resected aneurysm showed myxomatous degeneration. There were no signs of the inflammatory processes. The aneurysm formation in this case was considered to be due to the myxomatous degenerative changes of the anterior leaflet of the mitral valve. Fifteen cases of true aneurysm of the mitral valve reported in Japan were reviewed.