冠状動脈造影像に異常を認めなかった僧帽弁前乳頭筋完全断裂の1例

Complete Anterior Papillary Muscle Rupture with Angiographically Normal Coronary Arteries；Report of a Case

はじめに　僧帽弁乳頭筋断裂（PMR）は心筋梗塞（MI）に伴う重篤な機械的合併症の一つである．われわれは，術前の冠状動脈造影像上では異常を認めなかった前乳頭筋完全断裂の1例を経験した．僧帽弁置換術を行って救命し，術後精査で乳頭筋に限局した新旧MIの混在に起因するまれな症例と診断したので報告する．

We present a case of complete anterior papillary muscle rupture （PMR） due to localized papillary muscle infarction, without significant coronary artery disease. A 69-year-old woman was transferred to our hospital because of acute orthopnea and cardiogenic shock. Echocardiography showed severe mitral regurgitation due to anterior PMR, and emergency coronary angiography revealed no obstructive disease in the coronary arteries. Emergency mitral valve replacement was performed with intra-aortic balloon pumping support. Intraoperatively, the anterolateral papillary muscle was found to be completely ruptured. With maximal posterior leaflet preservation, mitral valve replacement was successfully performed. Her postoperative course was uneventful. Pathologic examination showed both old fibrosis and new ischemic lesion in the same resected papillary muscle. It could be speculated that repeated localized subendocardial infarction caused so-called spontaneous PMR.