[Partial Rupture of an Anterior Papillary Muscle without Preoperative Diagnosis of Acute Myocardial Infarction;Report of a Case].

: We report a case of partial rupture of an anterior papillary muscle without diagnosis of acute myocardial infarction before operation. A 70-year-old woman who had been in the psychiatry department for schizophrenia was admitted to our hospital by emergency for shock and dyspnea. Echocardiography demonstrated severe mitral regurgitation with prolapse of the anterior leaflet, and coronary angiography revealed significant stenosis of the 1st diagonal branch but no total occlusion of the coronary artery. In an emergency operation, partial rupture of the anterior papillary muscle and thickening of the posterior leaflet were found, and mitral valve repair was performed. Her postoperative course was uneventful. Postoperative pathological examination revealed acute myocardial infarction.