Li Zhaohuan, Tang Hong, Feng Yuan
Department of Cardiology, West China Hospital of Sichuan University, Chengdu Sichuan 610041, PR China.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2008 Nov;22(11):1344-8.
To analyze longitudinal motion of infarcted myocardium and ischemic myocardium with a new echocardiographic technology of velocity vector imaging (VVI), and to assess its accuracy.
From December 2007 to January 2008, 6 patients suffered acute anterior myocardial infarction (MI group), 9 patients had myocardial ischemia (over 70% stenosis of anterior descending branch, MS group) and 16 healthy subjects (control group) were included. The long axis view and 2-chambers view of left ventricle at the apex of heart were acquired with Siemens Sequoia 512 ultrasound system. The longitudinal velocity, displacement, strain and strain rate were analyzed with off-line Syngo US workplace software.
In normal myocardial group, longitudinal peak systolic velocity (Vs) and peak displacement (D) decreased progressively from base level to apex level in anterior wall and anterior septum (P < 0.05), while peak strain (S) and peak systolic strain rate (SRs) kept the same in three levels (P > 0.05). S and SRs significantly decreased in all segments of infarcted myocardium (P < 0.05), compared with normal and ischemic myocardium. In ischemic myocardium, only base and middle segmental S of anterior wall decreased (P < 0.05). A myocardial S lower than -6.94% in at least one ventricular segment showed best sensitivity (100%) and specificity (100%) for detecting an infarcted left ventricle. A myocardial SRs lower than -0.81% at least in one ventricular segment showed 100% sensitivity and 80% specificity, and lower than -0.46% showed 83% sensitivity and 100% specificity.
VVI is a useful tool for assessing myocardial regional function. Especially, S and SRs are useful predictors of the presence of regional dysfunction in infarcted myocardium.
采用一种新的超声心动图技术——速度向量成像（VVI）分析梗死心肌和缺血心肌的纵向运动，并评估其准确性。
选取2007年12月至2008年1月期间的6例急性前壁心肌梗死患者（心肌梗死组）、9例心肌缺血患者（前降支狭窄超过70%，心肌缺血组）以及16例健康受试者（对照组）。使用西门子Sequoia 512超声系统获取心尖四腔心切面和两腔心切面的左心室长轴图像。采用离线Syngo US工作场所软件分析纵向速度、位移、应变和应变率。
在正常心肌组中，前壁和前间隔的纵向收缩期峰值速度（Vs）和峰值位移（D）从心底向心尖逐渐降低（P < 0.05），而峰值应变（S）和收缩期峰值应变率（SRs）在三个层面保持不变（P > 0.05）。与正常心肌和缺血心肌相比，梗死心肌各节段的S和SRs均显著降低（P < 0.05）。在缺血心肌中，仅前壁基底段和中间段的S降低（P < 0.05）。至少一个心室节段的心肌S低于-6.94%时，检测梗死左心室的敏感性（100%）和特异性（100%）最佳。至少一个心室节段的心肌SRs低于-0.81%时，敏感性为100%，特异性为80%；低于-0.46%时，敏感性为83%，特异性为100%。
VVI是评估心肌局部功能的有用工具。特别是，S和SRs是梗死心肌局部功能障碍存在的有用预测指标。
