Regional myocardial contractile reserve assessed by strain echocardiography and the response to cardiac resynchronization therapy.

Background: Overall response rate to cardiac resynchronization therapy (CRT) is still not optimal. The aim of the study was to evaluate the influence of the regional myocardial contractile reserve during dobutamine infusion in the area of left ventricular (LV) electrode on the response rate and reverse remodeling LV in patients receiving CRT.

Methods: Biventricular pacemaker was implanted in 41 consecutive patients (33 men, mean age 62 ± 10 years) with LV ejection fraction (LVEF) ≤ 35%, New York Heart Association class III and QRS duration ≥ 120 ms.