Author + information
Cardiac resynchronization therapy (CRT) is efficacious in the treatment of chronic heart failure (CHF); however, due to its non-physiological attribute, some patients are unresponsive. The present study used rate-adaptive atrioventricular delay (RAAVD) to track the physiological atrioventricular delay and investigated the effects of left univentricular pacing on CRT.
A total of 58 cases with chronic heart failure fulfilling the indication of CRT Class I were enrolled in the study. Based on the principle of 1:1 pairing, they were categorized into left univentricular pacing by RAAVD and the standard biventricular pacing groups. Preoperative and postoperative electrocardiography QRS duration, echocardiographic indicators, quality of life, cardiac function, and annual treatment cost were estimated. The standard deviation (RS/R-SD5) of the S/R ratio in lead V1 at five heart rate segments in the left univentricular pacing by RAAVD was calculated, and the accuracy of RAAVD in tracking the physiological AV delay was evaluated.
The comparison between the left univentricular pacing by RAAVD group and the standard biventricular pacing group after operation showed a significantly reduced QRS duration (136±11 vs. 145±11ms, P<0.05), increased AVVTI (21.82±2.25 vs. 20.45±2.13cm, P<0.05), reduced IVMD (64.30±12.29 vs. 71.39±13.64 ms, P<0.05), decreased MRA (3.09±1.21 vs. 3.73±1.19cm2, P<0.05), and reduced average annual treatment cost (1.31±0.1 vs. 2.20±0.2 million Yuan, P<0.05). The RS/R-SD5 in the left univentricular pacing by RAAVD group was negatively correlated with the improvements in the cardiac function (r=-0.394, P=0.031).
The left univentricular pacing by RAAVD acquires treatment effects similar to those of the standard biventricular pacing, which is an economically and physiologically effective method for biventricular systolic resynchronization in the treatment of CHF.