A clinical research of left ventricular systolic synchronization in patients with complete right bundle brunch block using velocity vector imaging

Objective To analyze the left ventricular synchronicity in patients with complete right bundle brunch block (CRBBB) by velocity vector imaging (VVI), and to provide reliable basis for evaluating left ventricular patho-physiological function changes in patients with CRBBB. Methods The left ventricular systolic peak time of longitudinal strain (Tsl), radial strain (Tsr), circumferential strain (Tsc) and the rotation angle (Tra) were obtained by VVI from 31 CRBBB patients and 26 healthy volunteers. Results The systolic dyssynchrony indexes of longitudinal (Tsl-SD), radial (Tsr-SD), circumferential (Tsc-SD), and rotational (Tra-SD) motion in 18 segment of left ventricular in CRBBB group and control group were (27.65±6.78) ms vs (26.55±6.99) ms, (32.63±11.82) ms vs (26.63±6.70) ms, (42.81±9.72) ms vs (30.53±8.71) ms, and (37.01±7.73) ms vs (27.67±7.11) ms, respectively. The systolic dyssynchrony indexes of circumferential and rotary motion in the CRBBB group were significantly greater than that in control group, and no significant differences were observed in longitudinal and radial dyssynchrony indexes between two groups (t=4.911, 4.980, both P=0.000). Conclusions Compared with control group, left ventricular circumferential and rotary asynchnization index increased in CRBBB group . VVI can reflect the mechanical movement synchrony of left ventricule in various dimensions. Key words: Velocity vector imaging; Completed right bundle branch block; Ventricular function, left