Quantifying Mitral Regurgitation: Added Value of Three-Dimensional Echocardiography

Current three-dimensional (3D) echocardiographic technology, including live 3D transesophageal echocardiography and single-beat 3D color Doppler imaging, are providing valuable new insight into the mechanism and quantification of mitral valve dysfunction. In this review we discuss important applications of 3D volumetric leaflet imaging with emphasis on the distinction between organic and functional mitral regurgitation. We also discuss the added benefit of current and emerging 3D color Doppler methods for the quantification of mitral regurgitation severity. The limitations of the 2D proximal isovelocity surface area method are discussed, along with potential solutions provided by 3D color Doppler imaging methods that do not require assumptions about the converging flow geometry. Methods to directly measure the vena contracta area of a regurgitant jet are presented along with recent validation studies comparing this method to a reference standard of cardiac MRI. In brief, we review the established and emerging applications of 3D color Doppler techniques for the quantification of mitral regurgitation severity.     

体元模型动态三维重建定量二尖瓣狭窄的二尖瓣体积

目的：体元模型动态三维重建技术的发展为我们定量心脏结构的病理变化提供了方便。本研究旨在评价该技术定量二尖瓣狭窄患者二尖瓣体积的准确性以及定量二尖瓣体积潜在的临床应用价值。研究对象为从１２例二尖瓣换瓣术后获得的离体二尖瓣标本，３６例二尖瓣狭窄患者（年龄４７±９６岁）和１０例正常人（年龄４３７±８４岁）。图像采集采用美国ＨｅｗｌｅｔＰａｃｋａｒｄＳｏｎｏｓ２５００超声诊断仪和５ＭＨｚ多平面经食管超声探头。三维重建采用德国ＴｏｍＴｅｃＥｃｈｏｓｃａｎ计算机工作站。采用三维提取法将二尖瓣单独提取分析其体积。结果：所有研究对象均获得满意的三维重建。三维重建测定的离体二尖瓣体积为４９５±１５２ｍｌ，实测值为４９０±１５７ｍｌ，二者差别无显著意义（Ｐ＞００５），并且高度相关（ｒ＝０９８，Ｐ＜００００５）。三维重建测定的二尖瓣狭窄患者二尖瓣膜的体积大于正常人，分别为９０±２２ｍｌ和４５±０７ｍｌ，差别有显著意义（Ｐ＜０００１）。结论：体元模型动态三维重建能够准确地定量二尖瓣体积，二尖瓣狭窄者的二尖瓣体积大于正常人，本研究为今后二尖瓣球囊扩张术前病例的选择提供了客观依据。     

经胸及经食管超声心动图在二尖瓣成形术中的应用价值

目的 探讨经胸及经食管超声心动图在二尖瓣成形术中的应用价值.方法 术前经胸超声心动图(TTE)对二尖瓣脱垂的具体部位进行定位,并与手术所见对比.术中应用经食管超声心动图(TEE)实时监测评价二尖瓣成形术的效果.结果 本组60例二尖瓣脱垂患者,TTE诊断67个瓣叶93个分区出现脱垂,术中发现78个瓣叶104个分区脱垂,超声诊断符合率分别为85.9%和89.4%.术中发现二尖瓣反流TEE分级0级38例,1级10例,2级5例,3级7例.0级和1级者视为手术成功,而3级者因反流较多改行二尖瓣置换术.结论 TTE及TEE二者结合在二尖瓣成形术中具有非常重要的应用价值.