Acute mitral valve regurgitation due to complete rupture of anterior papillary muscle mimicking mitral valve vegetation.

We report the successful treatment of a 77-year-old man after a difficult diagnosis of mitral valve regurgitation resulting from complete rupture of the anterior papillary muscle. The patient with cardiogenic shock was an emergency admission. An electrocardiogram showed acute lateral wall myocardial infarction. He had complications of leukocytosis and a high-grade fever. Transesophageal echocardiography seemed to show the appearance of a large area of vegetation attached to the anterior mitral valve leaflet and aortic non-coronary cusp, resulting in severe mitral regurgitation. We performed coronary angiography, which showed complete obstruction of the circumflex coronary artery. We determined that the condition was caused by infective endocarditis. Emergency surgery showed the complete rupture of the anterior papillary muscle, but there was no vegetation. The mitral valve was replaced with a bioprosthetic valve and the circumflex coronary artery was bypassed with a saphenous vein graft. Pathological examination revealed mitral valve to be non-mycotic, and the postoperative course was uneventful.