Mechanistic insights into transient severe mitral regurgitation

Acute mitral regurgitation (AMR), a known complication of acute coronary syndromes, is usually associated with posterior papillary muscle dysfunction/rupture. In severe cases, management of AMR requires surgical intervention. Reversible severe AMR in patients in the absence of left ventricular systolic dysfunction and coronary artery stenosis may result from processes which cause transient subendocardial ischemia, such as intermittent episodes of hypotension or coronary artery vasospasm. We present two cases of reversible transient AMR due to subendocardial and/or endocardial ischemia, both of which offer insight into the mechanism of transient severe AMR.急性二尖瓣反流（Acute mitral regurgitation, AMR）是急性冠脉综合征的已知并发症，通常与后乳头肌功能不全或断裂相关。病情严重时，急性二尖瓣反流的管理需采取手术干预。若患者不存在左心室收缩功能障碍与冠状动脉狭窄，却出现可逆性重度急性二尖瓣反流，其诱因可能为引发一过性心内膜下缺血的病理过程，例如间歇性低血压发作或冠状动脉痉挛。本文报告2例由心内膜下及/或心内膜缺血引发的可逆性一过性急性二尖瓣反流病例，两例均为阐明重度一过性急性二尖瓣反流的发病机制提供了参考。