Secondary mitral regurgitation (MR) is a common finding in patients with dilated cardiomyopathy, and it is associated with poor outcomes. It is the result of incomplete systolic closure of the mitral valve (MV) as a consequence of left ventricular dilatation, papillary muscle displacement with impaired systolic shortening, and mitral leaflet tethering. MV surgery may be performed in cases of significant secondary MR despite guideline-directed medical therapy. However, MV repair, which is most commonly performed with an undersized ring annuloplasty, is associated with a 30-60% recurrence of moderate or greater MR at mid-term follow-up. To improve MV repair durability, several adjunctive subvalvular procedures have been proposed, one of which is the addition of papillary muscle approximation utilizing a papillary muscle sling. Recent studies comparing the outcomes of a conventional undersized ring annuloplasty with a MV repair utilizing a papillary muscle sling have reported a significant reduction in recurrent moderate or severe MR, greater left ventricular reverse remodeling, and improved MV apparatus geometry with the addition of the papillary muscle sling. We present a comprehensive review of the pathophysiology of secondary MR, and the rationale and clinical outcomes of MV repair with papillary muscle sling placement for the treatment of secondary MR.

中文翻译：

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二尖瓣和瓣膜下修复术治疗二尖瓣反流：乳头肌吊带的原理和临床结果。

继发性二尖瓣关闭不全（MR）是扩张型心肌病患者的常见发现，并且与不良预后相关。这是由于左心室扩张，乳头肌移位，收缩期缩短受损和二尖瓣束缚而导致的二尖瓣（MV）收缩压关闭不完全的结果。尽管有指南指导的药物治疗，但在发生严重继发性MR的情况下仍可进行MV手术。然而，在中期随访中，MV修复通常是通过小尺寸的环形瓣环成形术进行的，与中度或更大MR的30-60％复发相关。为了提高MV修复的耐久性，已经提出了几种辅助的瓣膜下手术，其中之一是利用乳头肌吊带增加乳头肌逼近。最近的研究比较了常规小环瓣环成形术与使用乳头肌吊带进行MV修复的结果，发现复发性中度或重度MR明显降低，左心室反向重塑更大，并通过添加乳头肌改善了MV装置的几何形状吊索。我们目前对继发性MR的病理生理学以及乳头肌悬带放置MV修复治疗继发性MR的基本原理和临床结果进行了全面回顾。