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

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. Key words: Echocardiography; Coronary disease; Ventricular function,left; Velocity vector imaging