二维斑点追踪成像对冠心病左室心肌局部收缩功能异常的研究

Clinical study of left ventricular segment wall motion abnormality by two-dimensional speckle tracking imaging

目的运用二维斑点追踪成像(STI)测量正常人及心绞痛、心肌梗死患者左心室各节段的二维应变值,探讨二维斑点追踪技术对节段性心肌缺血的临床价值。方法心绞痛患者73例,心肌梗死患者67例,健康对照组50例,分别采集其左心室长轴和短轴方向的二维动态图像,测量心肌收缩期峰值的纵向应变、径向应变和圆周应变。结果对照组应变曲线排列规律,纵向应变由基底部到心尖部递增;同一水平室间隔周向应变较高;径向应变在同一水平不同节段分布较一致。心绞痛组、心肌梗死组缺血室壁节段纵向应变、径向应变和圆周应变减低,应变曲线紊乱;心绞痛组纵向应变、径向应变较对照组减低(P<0.05),心肌梗死组纵向应变、径向应变和圆周应变较对照组和心绞痛组均减低(P<0.05)。结论 STI能够准确测量左室心肌节段的二维应变值,定量评价心肌缺血程度,纵向应变和径向应变是冠心病早期心肌缺血的敏感指标。

Objective To investigate the clinical value of two - dimensional speckle tracking imaging （STI） in segmental myocardial ischemia by measuring the two - dimensional strain of left ventricular segments in healthy subjects and patients with coronary heart disease （CHD）. Methods High frame rate images were recorded at the left ventricular long and short- axis view. The peak systolic radial strain （RS） , circumferential strain （CS） , and longitudinal strain （LS） were measured by 2D strain software in 67 patients with myocardial infarction ,73 patients with angina pectoris and 50 normal subjects. Results In the normal subjects,LS value was increased from base to apex, RS value of different segments at the same level had no significant difference. CS value of intercentricular septum was higher than that in the other segments at the same level. There was significant difference in LS, RS value between group of angina pectoris and normal subjects （P 〉 0.05 ）, while there was no significant difference in CS value （ P 〉 0.05 ）. LS, RS and CS value in group of myocardial infarction were lower than those in the normal subjects and group of angina pectoris respectively （ P 〈 0.05 ）. Conclusion STI has great value in quantitative analysis of segment wall motion abnormality of left ventricle because it can measure 2D straining value exactly. LS and RS value both can be used as sensitive indexes of early myocardial ischemia.