A prospective study to evaluate the efficacy of an intracardiac electrogram-based atrioventricular and interventricular intervals optimization method in cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) with biventricular pacing improves cardiac function, functional capacity and quality of life in selected patients with heart failure. The current study aimed to evaluate the efficacy of the intracardiac electrogram (IEGM)-based optimization method, QuickOpt(TM), in Chinese patients treated with CRT.Aortic time velocity integrals (AVTI) achieved at the sensed atrioventricular (AV), paced AV and interventricular (VV) interval settings recommended by both QuickOpt(TM) and standard echocardiographic optimization were measured in 101 patients. Consistency and the strength of the relationship between the two timing cycle optimization methods were assessed by intra-class correlation coefficient (ICC).The ICC showed good agreement and correlation with what the AVTI achieved at the optimal sensed AV (ICC = 0.9683 (0.9535 - 0.9785)), paced AV (ICC = 0.9642 (0.9475 - 0.9757)) and VV (ICC = 0.9730 (0.9602 - 0.9817)) interval settings determined by the two optimization methods. The average time required by echocardiographic optimization and by QuickOpt(TM) were (78.32 ± 32.40) minutes and (1.98 ± 1.64) minutes respectively (P0.0001).The QuickOpt(TM) algorithm provides a quicker, simpler and reliable alternative to the standard method for timing cycle optimization.