Pirat Bahar, Khoury Dirar S, Hartley Craig J, Tiller Les, Rao Liyun, Schulz Daryl G, Nagueh Sherif F, Zoghbi William A
Methodist DeBakey Heart Center Echocardiography Laboratory and Baylor College of Medicine, Division of Cardiology, Houston, Texas 77030, USA.
J Am Coll Cardiol. 2008 Feb 12;51(6):651-9. doi: 10.1016/j.jacc.2007.10.029.
The aim of this study was to validate a novel, angle-independent, feature-tracking method for the echocardiographic quantitation of regional function.
A new echocardiographic method, Velocity Vector Imaging (VVI) (syngo Velocity Vector Imaging technology, Siemens Medical Solutions, Ultrasound Division, Mountain View, California), has been introduced, based on feature tracking-incorporating speckle and endocardial border tracking, that allows the quantitation of endocardial strain, strain rate (SR), and velocity.
Seven dogs were studied during baseline, and various interventions causing alterations in regional function: dobutamine, 5-min coronary occlusion with reperfusion up to 1 h, followed by dobutamine and esmolol infusions. Echocardiographic images were acquired from short- and long-axis views of the left ventricle. Segment-length sonomicrometry crystals were used as the reference method.
Changes in systolic strain in ischemic segments were tracked well with VVI during the different states of regional function. There was a good correlation between circumferential and longitudinal systolic strain by VVI and sonomicrometry (r = 0.88 and r = 0.83, respectively, p < 0.001). Strain measurements in the nonischemic basal segments also demonstrated a significant correlation between the 2 methods (r = 0.65, p < 0.001). Similarly, a significant relation was observed for circumferential and longitudinal SR between the 2 methods (r = 0.94, p < 0.001 and r = 0.90, p < 0.001, respectively). The endocardial velocity relation to changes in strain by sonomicrometry was weaker owing to significant cardiac translation.
Velocity Vector Imaging, a new feature-tracking method, can accurately assess regional myocardial function at the endocardial level and is a promising clinical tool for the simultaneous quantification of regional and global myocardial function.
本研究旨在验证一种用于超声心动图定量分析局部功能的新型、角度无关的特征跟踪方法。
一种新的超声心动图方法，即速度向量成像（VVI）（西门子医疗解决方案公司超声部门的syngo速度向量成像技术，加利福尼亚州山景城）已被引入，它基于结合斑点和心内膜边界跟踪的特征跟踪技术，能够定量分析心内膜应变、应变率（SR）和速度。
对7只犬在基线状态以及导致局部功能改变的各种干预措施下进行研究：多巴酚丁胺、5分钟冠状动脉闭塞并再灌注1小时，随后输注多巴酚丁胺和艾司洛尔。从左心室的短轴和长轴视图获取超声心动图图像。节段长度超声微测晶体用作参考方法。
在局部功能的不同状态下，VVI能很好地跟踪缺血节段收缩期应变的变化。VVI测量的圆周和纵向收缩期应变与超声微测法之间具有良好的相关性（分别为r = 0.88和r = 0.83，p < 0.001）。非缺血基底部节段的应变测量结果也显示这两种方法之间具有显著相关性（r = 0.65，p < 0.001）。同样，两种方法在圆周和纵向SR方面也观察到显著相关性（分别为r = 0.94，p < 0.001和r = 0.90，p < 0.001）。由于明显的心脏移位，心内膜速度与超声微测法测量的应变变化之间的关系较弱。
速度向量成像，一种新的特征跟踪方法，能够在心内膜水平准确评估局部心肌功能，是同时定量分析局部和整体心肌功能的一种有前景的临床工具。
