Abstract:Objective: To find the dynamic regional myocardial function and its systolic synchronization in patients of chronic heart failure who were treated with cardiac resynchronization therapy(CRT), The longitudinal strain radial strain, circumferential strain and rotation were observed. Methods: Fifteen patients suffering from heart failure, who received CRT, were select. Speckle tracking imaging in addition to standard echocardiography were performed prior to CRT, one week and 3 months after CRT. We observed the longitudinal strain, radial strain, circumferential strain and rotation, as well as time to peak strain and peak rotation. The standard deviation of time to each peak systolic strain and rotation (Ts-sl-SD, Ts-Sr-SD, Ts-sc-SD, Ts-srot-SD)were calculated. Results: One week after CRT, the Ts-sl-SD shortened(P<0.05), but there were no significant difference in Ts-Sr-SD, Ts-sc-SD, and Ts-srot-SD(P<0.05). Three months after CRT, all of them were shortened(P<0.05). The longitudinal and circumferential strain increased one week after CRT compared with those prior to CRT(P<0.05). Three months after CRT, not only longitudinal and circumferential strain but radial strain and rotation increased(P<0.05). Conclusions: Regional myocardial function can be valued by speckle tracking imaging. There is dynamic change in regional myocardial function of different direction of cardiac contraction in patients who response to CRT.