[Mitral valve aneurysm in a patient with mitral regurgitation: a case report].

A 66-year-old man admitted to our hospital complaining of severe dyspnea. Echocardiography demonstrated severe mitral regurgitation and an abnormal echo at the anterior leaflet of the mitral valve. It was a persistent bulge that protruded toward the left atrium throughout systole and diastole. Left ventriculography also demonstrated the same abnormal shadow of the mitral valve. At the operation, it was seen that two of the chordae tendineae of the anterior leaflet had ruptured and a small aneurysm, approximately 10 mm in length, originated from the lateral part of the leaflet. The aneurysm protruded into the left atrium and had neither rupture nor perforation. Because the aneurysm of the mitral valve was too large to resect and repair the valve, it was replaced with St. Jude Medical Valve (29 M). IABP was needed at the weaning from cardiopulmonary bypass, but he recovered gradually well afterwards. The excised anterior leaflet showed myxomatous degeneration, but had no vegetation and rheumatic change. Microscopic examination of the valve aslo revealed myxomatous degeneration and no signs of the inflammation.