Contributions of different components of myocardial motion to left ventricular contraction by two-dimensional speckle tracking echocardiography

Abstract

Objective To decompose left ventricular contractile motions and analyze the corresponding contributions of different components to left ventricular systolic function. Methods Sixty-nine healthy adults with normal left ventricular eject fraction (LVEF) were recruited. Two-dimensional speckle tracking echocardiography was performed by GE Vivid E9 system, and strain parameters were analyzed by EchoPac software. Correlation and multiple stepwise regression analysis were performed to analyze the contributions of different components of myocardial motion to left ventricular contraction. Results Global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS) and twist were all significantly correlated with LVEF (r=-0.668, P<0.001; r=-0.552, P<0.001; r=0.335, P=0.006; r=0.428, P<0.001). Significant correlations were found between all the strain parameters, except for GRS and twist. Multiple stepwise regression adjusted for sex, and age showed that the uni-contributions of GLS, GCS, GRS and twist to LVEF were 21.3%, 13.0%, 7.5%, 8.8%, respectively. However, with all strain parameters in the general regression model, only GLS and twist were still significantly related with LVEF (R2=0.566, P<0.001). Conclusions The contributions of various components of myocardial motion to left ventricular contraction in healthy adults are different. Although every component is significantly related with LVEF, the longitudinal and twist motion are most important in the integrated view. Key words: Two-dimensional speckle tracking imaging; Ventricular function, left; Myocardial strain