OBJECTIVEThe efficacy of cardiac resynchronization therapy (CRT) in patients with congestive heart failure and the potential factors associated with responder or nonresponder were investigated.

METHODSFifty three patients with congestive heart failure (42 with sinus rhythm and 11 with atrial fibrillation) underwent CRT were enrolled in this study. Conventional echocardiography and tissue Doppler imaging were performed in each patient before implantation and 6 month post implantation. Clinical response was defined as improvement of one NYHA functional class and echocardiographic response was defined as a reduction in LV end-systolic volume by > 15% or an increase of absolute value of LVEF > 5%.

RESULTSThe clinical response rate was 75% and echocardiographic response rate was 69.8% during 6 month follow-up. The echocardiographic response rate for patients with atrial fibrillation was lower than that for patients with sinus rhythm (45.5% vs. 76.2%, P < 0.05). In patients with sinus rhythm, higher response rate was seen in patients with widen QRS duration, lower pulmonary systolic pressure and prolonged left ventricular pre-ejection time (LVPT) while response rate was not affected by LVEF, left ventricular volume, NYHA functional class and intra-ventricular dyssynchrony.

CONCLUSIONSResponse rate to CRT was lower in patients with atrial fibrillation compared to patients with sinus rhythm. In patients with sinus rhythm, QRS duration, LVPT and pulmonary systolic pressure were useful parameters to predict the response to CRT.