Department of Clinical Technology, Kobe City Medical Center General Hospital, Kobe, Japan.
Basic Medical Science, Kobe City College of Nursing, Kobe, Japan.
Echocardiography. 2020 Nov;37(11):1716-1722. doi: 10.1111/echo.14896. Epub 2020 Oct 22.
Mitral annular disjunction is a structural abnormality of the mitral annulus fibrosus which is often associated with mitral leaflet prolapse. However, few reports have described mitral annular disjunction in mitral valve prolapse (MVP). This study aimed to investigate the characteristics of mitral annular disjunction in patients with severe mitral regurgitation (MR) caused by MVP.
We reviewed 185 consecutive patients with severe MR caused by fibroelastic deficiency (FED) and Barlow's syndrome from March 2009 to December 2010. The upper limit of the disjunction was defined at the level of the posterior scallop's insertion into the left atrial wall, whereas the lower limit was defined at the level of the left atrium's connection to the ventricular myocardium. The distance between the two levels was called mitral annular disjunction. Prolapse sites in FED patients were categorized into anterior leaflet, posterior leaflet, and commissure groups. Patients with a disjunction distance of ≥2 mm were diagnosed with mitral annular disjunction.
Annular disjunction was found in 45 patients (24%). Among them, the most common site of prolapse was the posterior leaflet (n = 35, 77.8%). During a median follow-up of 20.3 years, arrhythmic events and sudden death occurred in seven patients (3.8%).
Mitral annular disjunction was detected in 24% of patients with severe MR and in 90% of the patients with Barlow's syndrome. There were significant differences at its sites of prolapse in FED patients. The presence and site of prolapse with mitral annular disjunction should be actively determined in FED patients.
二尖瓣环分离是二尖瓣环纤维弹性组织异常的一种表现，常与二尖瓣叶脱垂有关。然而，很少有报道描述二尖瓣脱垂（MVP）中的二尖瓣环分离。本研究旨在探讨 MVP 引起的重度二尖瓣反流（MR）患者中二尖瓣环分离的特征。
我们回顾了 2009 年 3 月至 2010 年 12 月期间因纤维弹性缺失（FED）和巴洛氏综合征引起的 185 例重度 MR 连续患者。分离的上限定义为后瓣叶插入左心房壁的水平，下限定义为左心房与心室心肌连接处的水平。两个水平之间的距离称为二尖瓣环分离。FED 患者的脱垂部位分为前瓣叶、后瓣叶和交界组。分离距离≥2mm 的患者被诊断为二尖瓣环分离。
发现 45 例（24%）患者存在瓣环分离。其中，最常见的脱垂部位是后瓣叶（n=35，77.8%）。在中位数为 20.3 年的随访期间，7 例患者（3.8%）发生心律失常事件和猝死。
在重度 MR 患者中，有 24%的患者存在二尖瓣环分离，而在巴洛氏综合征患者中，有 90%的患者存在二尖瓣环分离。FED 患者的脱垂部位存在显著差异。在 FED 患者中，应积极确定是否存在二尖瓣环分离及其脱垂部位。
