The prediction of response to cardiac resynchronization therapy by real-time three-dimensional speckle tracking echocardiography

Objective To evaluate left ventricular(LV) contractility and mechanical synchronization in chronic heart failure patients undergoing cardiac resynchronization therapy (CRT) before and 6 months after operation by three-dimensional speckle tracking imaging(3D-STI) and two dimensional speckle tracking imaging(2D-STI), and to compare the value of the two methods in prediction of CRT response. Methods Forty-one patients with chronic heart failure underwent CRT were involved. Three-dimensional and two-dimensional longitudinal strain (LS-3D, LS-2D) and their standard deviations of the time to peak longitudinal strain (Tls-16SD-3D, Tls-16SD-2D) were analyzed before and after CRT. Ten CRT patients and 10 healthy controls were chosen to evaluate the reproducibility of 2D and 3D STI parameters. Results At 6-month follow-up after CRT, echocardiography indices in the response group were significantly improved (all P<0.05) while only LVEF and LS-3D were improved in nonresponse group. The area under the ROC curve for LS-3D, Tls-16SD-3D and LS-2D were 0.816, 0.845 and 0.661 respectively(P<0.05). The reproducibility of 3D-STI indices was superior to that of 2D-STI, especially in CRT patients. Conclusions Both 2D-STI and 3D-STI can evaluate LV myocardial contractility and the mechanical dyssynchronization, however, 3D-STI is superior in prediction value and reproducibility compared with 2D-STI. Key words: Echocardiography; Heart failure; Ventricular function; Cardiac resynchronization therapy; Speckle tracking imaging