斑点追踪法测量二尖瓣环位移评估左心室收缩功能

目的 应用最新的超声二维(2D)斑点追踪显像技术测定二尖瓣环位移(MAD),分析其与实时三维超声(RT3D)所测得的左心室射血分数(LVEF)之间的相关性.方法 研究对象为临床确诊的扩张型心肌病(DCM)患者49例(DCM组),平均(51±14)岁;43名年龄(46岁±14岁)相匹配的健康志愿者作为对照组.采用Philips Sonos iE33超声仪,取心尖四腔观采集2D、RT3D全容积图像,将2D及3D图像输入QLAB 6.2工作站分别获取MAD各参数及RT3D-LVEF值.结果 DCM组的MAD各项测值均显著低于对照组(P均＜0.01).MAD各测值与3D-LVEF之间相关性良好(P＜0.01), 各测值的可重复性均较高.MAD各测值中,以胸壁为参考点的瓣环中点最大位移占左心室长径百分比(TMADm%)与LVEF相关性最好, 且重复性最高.结论 MAD能客观反映左心室的收缩功能.二维斑点追踪方法简便易行,可重复性高,有望成为临床评价左心室收缩功能的一个新的、甚至可替代LVEF的指标.

Evaluation of left ventricular global systolic function with two-dimensional speckle tracking of mitral annular displacement

Objective To investigate the preliminary value of mitral annular displacement (MAD) with two-dimensional speckle tracking in evaluating left ventricular systolic function. Methods Forty-nine patients with dilated cardiomyopathy, aged 51±14 years (DCM group), and 43 age-matched (46±14 years) normal subjects (control group) were enrolled in this study. Two-dimensional and real-time three-dimensional (RT3D) imaging were obtained all at the apical four-chamber view. The parameters of MAD and RT3D-LVEF were obtained using off-line QLAB software. Results Compared with control group, MAD reduced significantly in DCM group (P＜0.01). The parameters of MAD correlated positively with LVEF (P＜0.01). The intra- and inter-observer variabilities for measurement of MAD were low. When one point was placed at the chest wall, the ratio of long axis shortening correlated best with LVEF among all the data of MAD. Conclusion Based on two-dimensional speckle tracking imaging, MAD is a rapid and reproducible method of determining LV global systolic function, may even replace LVEF in the future.