二尖瓣反流经导管介入微创治疗新进展

随着微创及介入治疗技术在心脏瓣膜病的治疗中不断发展,心脏瓣膜病治疗的适应证逐渐扩大,尤其在二尖瓣反流的介入治疗领域,各项实验技术成果在动物及临床实验当中取得显著效果。现介绍二尖瓣反流经导管介入治疗的新进展,并针对当前研究热点,重点对有关技术的临床研究进展做一综述。     

Relation of Mitral Annular Dilation with Dynamic Mitral Regurgitation in Patients with Rheumatic Mitral Regurgitation

Introduction: Dynamic mitral regurgitation (MR) is frequently investigated in patients with left ventricular systolic dysfunction (LVSD). Data about the dynamic MR in patients with organic valve disease are limited. The aim of this study was to evaluate the alteration of MR by exercise in patients with rheumatic valve disease (RVD). Methods: Asymptomatic patients with rheumatic MR and normal left ventricular function had been included in our study. Transthoracic echocardiography and Doppler measurements were performed at rest and just after submaximal exercise test performed with treadmill. Severity of MR was evaluated quantitatively by measuring effective regurgitant orifice area (EROA) with flow convergence method. Results: A total of 34 patients with rheumatic MR had been included. Severity of MR increased in 10 patients with exercise (Group 1) and decreased in 24 of them (Group 2). When the variables of two groups were compared; diastolic blood pressure after exercise, EROA, left atrial volume, left ventricular diastolic volume and mitral annular area values were significantly higher in Group 1 patients. A linear regression model was constructed by considering change of EROA by exercise the dependent, and the variables showing significant differences as the independents. Mitral annular area was found to be independently associated with EROA increase with exercise (R²= 0.499; P < 0.001). Conclusion: Mitral annular dilation is independently associated with increase of MR with submaximal exercise in asymptomatic patients with MR due to RVD with normal left ventricular function.     

二尖瓣关闭不全的介入治疗新进展

为了减轻二尖瓣关闭不全外科手术和体外循环所带来的创伤和风险,基于外科边对边缝合和瓣环成形的手术方式,近年来二尖瓣关闭不全的介入治疗得到了快速发展,包括经二尖瓣边对边修补术和瓣环成形术,前者经穿房间隔途径送入钳夹装置或负压抽吸缝合装置,钳夹或缝合前后瓣边缘,形成双孔二尖瓣,后者经右颈内静脉途径把缩环装置植入冠状静脉窦内,缩短瓣环前后径,以减轻二尖瓣反流。两种方法均已从动物实验过渡到临床试验,均显示了良好的治疗作用,但还需技术上的进一步改进和长期大规模的临床评价。     

Mitral Regurgitation Associated with Mitral Annular Dilation in Patients with Lone Atrial Fibrillation: An Echocardiographic Study

Background: Whether and how lone atrial fibrillation (AF) is associated with functional mitral regurgitation (MR) remain unclear. Method: We studied 12 lone AF patients without left ventricular (LV) dysfunction and/or dilatation, who underwent mitral valve annuloplasty for functional mitral regurgitation (MR). Ten lone AF patients without MR served as controls. Results: Lone AF Patients with MR had a greater mitral valve annular area and left atrial area than those without MR. There were no differences in LV volumes or LV ejection fraction. Conclusions: Therefore, we concluded that left atrial dilation and corresponding mitral annular dilation may cause MR in lone AF patients without LV dysfunction and/or dilatation.     

Mitral Valve Adaptation to Isolated Annular Dilation: Insights Into the Mechanism of Atrial Functional Mitral Regurgitation

Objectives

This study hypothesized that compensatory mitral leaflet area (MLA) adaptation occurs in patients with persistent atrial fibrillation (AF) without left ventricular (LV) dysfunction but has limitations that augment mitral regurgitation (MR). The study also explored whether asymmetrical annular dilation is matched by relative leaflet enlargement.

经导管缘对缘技术（MitraClip）治疗二尖瓣反流——亚太心脏病学会（APSC）专家共识

经导管二尖瓣缘对缘修复技术(代表产品:MitraClip),是一种经导管介入途径治疗二尖瓣反流(MR)的技术,西方循证医学证据已证实MitraClip是一种有效且安全的MR介入治疗技术。但是,在亚太地区患者群体中应用该类技术及产品的随机对照试验数据仍然有限。因此,亚太心脏病学会(APSC)召集专家组,通过详细回顾现有亚太地区MitraClip文献及临床治疗证据,制定共识建议,以更好地指导亚太地区的临床医师使用MitraClip治疗MR。本专家组讨论并制定的声明包括MitraClip在各种疾病中的应用,如:退行性MR,功能性MR和其他少见的指征,例如:急性MR,动力性MR,肥厚型梗阻性心肌病和三尖瓣反流。共识声明中的每一项条目都由专家成员投票表决,只有当80%专家表决同意或中立时才予通过。经过投票表决后,共有10项共识决议被认可,以指导心脏专科医师对准备使用MitraClip进行治疗的患者进行评估与管理。     

Mechanism of Mitral Regurgitation in Dilated Cardiomyopathy

Dilated cardiomyopathy is a condition characterized by chamber dilatation and impaired systolic function, resulting in the clinical manifestations of congestive heart failure. Mitral regurgitation occurs with varying frequency in dilated cardiomyopathy, and its detection depends on the diagnostic modality utilized. The presence of mitral regurgitation imposes an additional burden on the failing ventricle, and appears to be an independent prognostic indicator of mortality. The mechanism of mitral regurgitation in dilated cardiomyopathy is complex, controversial, and incompletely understood. The mitral apparatus consists of the left atrial wall, mitral annulus, mitral leaflets, chordae tendineae, papillary muscles, and left ventricular wall, and each of these components and the intimate interrelationship between these structures may contribute to the development of mitral regurgitation. Left atrial enlargement, reduced left atrial contractility, mitral leaflet retraction, abnormal vector of chordal tendineae pull, papillary muscle dysfunction (either asynergic contraction or malalignment), mitral annular dilatation, and changes in the size, shape, and function of the left ventricle have been suggested as possible mechanisms for the development of mitral regurgitation in dilated cardiomyopathy. The primary event in the development of mitral regurgitation appears to be left ventricular dilatation and dysfunction. Controversy persists as to whether the associated mechanism is annular dilatation, papillary muscle or free left ventricular wall dysfunction, or a combination of all, but recent echo-Doppler studies reviewed in this article support the notion that annular dilatation is the predominant mechanism. Improved understanding of the mechanism of mitral regurgitation in dilated cardiomyopathy may lead to a more aggressive approach with regard to pharmacological therapy, thus impacting on survival in this group of patients. (ECHOCARDIOGRAPHY, Volume 8, March 1991)