Cardiac resynchronization therapy (CRT) has been shown to reduce mortality in selected patients with heart failure (HF) [1], however its impact on ventricular arrhythmias (VAs) remains controversial. Several randomized controlled studies have demonstrated that while CRT significantly reduces mortality and HF progression, patients remain at increased risk of VAs [2,3]. Some data also indicate that left ventricular (LV) lead pacing alone could impose a potential proarrhythmic risk [4,5].Global scar burden and myocardial viability at the LV lead position play an important role in CRT response and VA occurrence [6][7][8][9]. A high LV pacing threshold (PT) at resynchronization device implantation may be a contributing factor to the adverse CRT outcome and could indicate a regional myocardial scar [10]. In addition, our previous study demonstrated that lower regional viability in the vicinity of the LV lead pacing site could be associated with increased risk of malignant tachyarrhythmias [11].In this analysis, we sought to determine the relationship between LVPT and myocardial viability at the LV lead position. We also hypothesized that high LVPT would be associated with potential occurrence of VAs. MethodsThe study complies with the Declaration of Helsinki. The study protocol was approved by The National Medical Ethics Committee and all patients gave a written informed consent before entering the study.
Background Atrioventricular (AV) node ablation with biventricular (BiV) pacemaker implantation is a feasible rate control strategy for symptomatic permanent atrial fibrillation (AF) with rapid ventricular response and tachycardia-induced heart failure (HF). However, certain controversy exists since BiV pacing delivers non-physiological ventricular resynchronization and does not return left ventricular (LV) activation times to those seen in individuals with intrinsically narrow QRS. Permanent His bundle pacing (HBP) is a physiological alternative to conventional and BiV pacing. By capturing the native conduction system, depolarization of the ventricles through the His-Purkinje system induces normal synchronous ventricular activation. Purpose The aim of the study was to compare short-term outcomes between BiV pacing and HBP after AV node ablation in HF patients with symptomatic permanent AF and narrow QRS. Methods A total of 25 consecutive HF patients with permanent AF and narrow QRS (≤110 ms) who underwent AV node ablation in conjunction with BiV pacing or HBP in our centre were enrolled. Post-implant QRS duration, echocardiographic data, and New York Heart Association (NYHA) functional class were assessed in short-term follow-up. Results Among 25 HF patients (aged 68 ± 7 years, 52% female, QRS 96 ± 9 ms, LVEF 37 ± 7%, NYHA II-IV), 13 received BiV pacing and 12 HBP. Implant and ablation procedures were acutely successful in both groups. In BiV group 1 patient had a LV lead dislodgement and 1 patient in the HBP group had an acute HB lead threshold increase after AV node ablation. In HBP group post-implant QRS duration was shorter compared to BiV (103 ± 15 ms vs. 177 ± 13 ms, p < 0.001). At a median follow-up of 6 months, patients treated with HBP had greater increase in LV ejection fraction compared to BiV (44 ± 10 vs. 37 ± 6, p = 0.045). A trend toward greater reduction of LV volumes (EDV 119 ± 54 ml vs. 153 ± 33 ml, p = 0.07; ESV 75 ± 34 ml vs. 97 ± 26 ml, p = 0.09) and improvement of NYHA class (2.1 ± 0.7 vs. 2.7 ± 0.8, p = 0.08) was also observed in HBP group compared to BiV group. Conclusion In rate control refractory HF patients with permanent AF and narrow QRS atrioventricular node ablation in conjunction with HBP demonstrated superior electrical resynchronization and greater increase in LV ejection fraction compared to BiV pacing. Larger prospective studies are warranted to address clinical outcomes between both pace and ablate strategies.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.