Effects of Right Ventricular Nonapical Pacing on Cardiac Function: A Meta-analysis of Randomized Controlled Trials

Background: A meta-analysis of randomized controlled trials ( RCTs) was conducted to compare the effects of right ventricular nonapical (RVNA) and right ventricular apical (RVA) pacing on cardiac function. Methods: A systematic literature search was performed using MEDLINE, EMBASE, and the Cochrane Library to identify RCTs comparing RVNA pacing with RVA pacing with follow-up >= 2 months. Twenty RCTs involving 1,114 patients were included. Results: Compared with RVA pacing, RVNA (mainly right ventricular septum [RVS]) pacing exhibited not only excellent pacing threshold and R-wave amplitude but also higher impedance. RVNA pacing showed a significant increase in left ventricular ejection fraction (LVEF) at the end of follow-up (weighted mean difference = 3.58, 95% confidence interval = 1.80-5.35), and the effects were observed in the following subgroups: 6-month follow-up, <= 12-month follow-up, >12-month follow-up, baseline LVEF <= 45%, and baseline LVEF >45%. RVS and RVA pacing significantly differed in improving LVEF (weighted mean difference = 4.82, 95% confidence interval = 2.78-6.87). In addition, RVNA pacing resulted in a narrower QRS duration, a smaller left ventricular end-systolic volume, and a lower New York Heart Association functional class. Conclusions: This meta-analysis found that RVNA (mainly RVS) pacing exhibited satisfactory long-term lead performance compared with RVA pacing and demonstrated beneficial effects in improving LVEF after the 6-month follow-up. Furthermore, it proved superior to RVA pacing in terms of interventricular synchrony and cardiac function.