速度向量成像应变指标评价冠心病患者左心室局部和整体收缩功能

Assessment of left ventricular regional and global systolic function in patients with coronary artery disease using strain parameter of velocity vector imaging

目的 应用速度向量成像（VVI）技术应变指标定量分析静息状态下冠心病患者左心室局部及整体收缩功能.方法 冠心病患者和健康志愿者各30例.采集心尖四腔、两腔及左室长轴观和二尖瓣环、乳头肌及心尖水平左室短轴观二维灰阶图像.按18节段法划分左室壁,分析各节段纵向（L）、周向（C）和径向（R）收缩期峰值应变（S）.将LS、CS心内、外膜测值之差分别定为纵向应变跨壁阶差（LSG）、周向应变跨壁阶差（CSG）;将左室壁所有节段各向应变平均值定为左室壁各向整体收缩期峰值应变并分别与左室射血分数（LVEF）作相关性分析.结果 A组为冠脉狭窄≤70%供血心肌,共176个节段,其LS及LSG明显低于对照组（P＜0.05）,CS、RS及CSG与对照组差异无统计学意义（P＞0.05）;B组为冠脉狭窄＞70%供血心肌,共132个节段,其LS、CS及RS均显著低于对照组（P＜0.05）,LSG及CSG与对照组差异无统计学意义（P＞0.05）.B组LS、RS、CS显著低于A组,LSG显著高于A组（P＜0.05）,CSG与A组差异无统计学意义（P＞0.05）.冠心病组各向整体收缩期峰值应变指标均与LVEF指标显著相关（P＜0.0001）,其中GLS与LVEF指标相关系数最高.结论 VVI技术应变指标可以准确评价冠心病患者左心室收缩功能异常.局部心肌LS、RS、CS、LSG及CSG的变化可以反映冠脉狭窄的严重程度;左室壁GLS可以作为评价冠心病患者左心室整体收缩功能的新指标.

Objective To assess left ventricular（LV） regional and global systolic function of patients with coronary artery disease using strain parameter of velocity vector imaging（VVI） technique in quiescent condition. Methods Thirty patients with coronary artery disease and 30 healthy volunteers were enrolled in this study. The two-dimensional gray scale images were obtained in apical 4-chamber view,apical 2-chamber view and long axis view of left ventricle, and three levels of the short axis views（mitral valve, papillary muscle and cardiac apex）. The LV wall was divided according to 18 segment model and the longitudinal,radial and circumferential systolic strain （SL, SR, SC） of each segment were analyzed. The difference between the epicardial and endocardial strain measurement were defined as strain gradient and the average of each strain component as global systolic strain. The correlation between global systolic strain of each strain component and the LV ejection fraction（LVEF） were analysed. Results Group A （coronary stenostic degree≤70%） included 176 segments, compared with control group, LS and LS gradient （LSG） decreased significantly from control group（ P 〈0.05）, while there was no significant difference in CS, RS and CS gradient （CSG） （ P 〉 0.05）. Group B （ coronary stenostic degree〉 70% ） included 132 segments, compared with control group, LS, CS and RS decreased significantly in group B （ P 〈 0.05）, while there was no significantly difference in LSG and CSG（ P 〉0.05）. There were also significant difference in LS, RS,CS and LSG between group A and B（ P 〈0.05）. Global systolic strain of each strain component shown significant correlation with LVEF （P 〈 0.0001 ）. And the global longitudinal systolic strain （GLS） correlated with LVEF most tightly. Conclusions Strain parameter of VVI technique could not only accurately analyze the LV systolic dysfunction but also reflect the stenostic degree of coronary artery. GLS could be a new index for LV systolic function assessment in patients with coronary artery disease.