Conduction System Pacing Improved Cardiac Functions - Myocardial Work and Functional Capacity in Heart Failure with Reduced Ejection Fraction and Right Bundle Branch Block

Q: What is the primary purpose of conduction system pacing in this study?

To assess echocardiographic and clinical outcomes of conduction system pacing in HFrEF patients with RBBB, focusing on cardiac functions, myocardial mechanics, energetics, and functional capacity.

Q: How were patients selected for conduction system pacing?

Patients had RBBB, QRS duration ≥130 ms, LVEF <35%, and NYHA II–IV symptoms despite 6 months of optimized medical therapy, and CSP was attempted using His bundle pacing or left bundle branch area pacing as a primary strategy.

Q: Which measured outcomes improved after CSP?

After CSP, QRS duration decreased, LVEF increased, global myocardial strain and myocardial work indices improved, NYHA class and 6-minute walk distance improved, and NT-proBNP decreased.

Sep 30, 2026

Upload by Blue Pony

Conduction system pacing (CSP) is evaluated as an alternative to biventricular pacing for heart failure with reduced ejection fraction (HFrEF) and right bundle branch block (RBBB). His bundle pacing and left bundle branch area pacing are attempted in patients with RBBB, QRS duration ≥130 ms, LVEF <35%, and NYHA II–IV symptoms after optimized medical therapy for 6 months. At baseline and 6 months, CSP reduces QRS duration, increases LVEF, improves myocardial strain and myocardial work indices, enhances NYHA class and 6-minute walk distance, and lowers NT-proBNP. Results support improved functional capacity and cardiac mechanics, pending multicenter randomized trials.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages14

Reading Time35 min

AccessFree to download

Abstract

1. Introduction

2. Materials

Article Conduction System Pacing Improved Cardiac Functions, Myocardial Work and Functional Capacity in Heart Failure with Reduced Ejection Fraction and Right Bundle Branch Block Anna Zsófia Tóth†, László Nagy *,†, Csaba Jenei , Arnold Péter Ráduly , Gábor Sándorfi, Krisztina Mária Szabó , Alexandra Kiss, László Tibor Nagy , Gerg ˝o István Szilágyi and Zoltán Csanádi Academic Editor: Fabian Sanchis-Gomar Received: 2 December 2025 Revised: 22 December 2025 Accepted: 25 December 2025 Published: 27 December 2025 Copyright: © 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license. Division of Cardiology, Department of Cardiology, Faculty of Medicine, University of Debrecen, Móricz Zsigmond krt. 22., H-4032 Debrecen, Hungary; [toth.anna@med.unideb.hu](toth.anna@med.unideb.hu) (A.Z.T.); [csanadi.zoltan@med.unideb.hu](csanadi.zoltan@med.unideb.hu) (Z.C.) * Correspondence: [dr.nagy.laszlo@med.unideb.hu](dr.nagy.laszlo@med.unideb.hu); Tel.: +36-30-550-2101 † These authors contributed equally to this work. Abstract Background/Objectives: Conduction system pacing (CSP) is a potential alternative tobiventricular pacing (BVP) in heart failure with reduced ejection fraction (HFrEF) and left bundle branch block (LBBB) or non-LBBB. Available data also suggest that unlike BVP, CSP may improve clinical outcome in patients with right bundle branch block (RBBB), although its effects on cardiac mechanics and energetics are ill-defined. Herein, we report on echocardiographic and clinical outcomes of CSP in this patient cohort. Methods: CSP either with His bundle pacing or LBB area pacing was attempted as a primary strategy in patients with RBBB, QRS duration ≥ 130 ms, LVEF < 35% and NYHA II-IV symptoms after optimized medical therapy for 6 months. Data on functional status, NT-proBNP and echocardiographic parameters were collected at baseline and 6 months after CSP. Results: CSP performed in 16 patients reduced QRS duration from 155.3 ± 12.8 ms to 130 ± 16.5 ms (p < 0.001), increased LVEF from 27 ± 7% to 33 ± 9%(p = 0.01), improved LV global longitudinal strain from −7 ± 3% to −10 ± 4%(p = 0.004) and improved LV peak strain dispersion from 126 ± 28 ms to 96 ± 23 ms (p = 0.004) . Global myocardial work index increased from 582 ± 277 mmHg% to 840 ± 306 mmHg%(p = 0.003), as did global constructive work (900 ± 374 mmHg% to 1203 ± 393 mmHg%; p = 0.006) and global work efficiency (from 71 ± 7% to 77 ± 8%; p = 0.004) . NYHA class (12.5% with NYHA II, 87 .5% with NYHA III before vs. 25% with NYHA I, 50% with NYHA II and 25% with NYHA III at 6 months; p = 0.002) and 6 min walk distance (from 354 ± 88 m to 411 ± 95 m; p = 0.003) improved, while NT-proBNP decreased (from 4093 ± 7215 ng/L to 2087 ± 2872 ng/L, p = 0.003) . Conclusions: CSP improved functional capacity and echocardiographic parameters related to cardiac functions and myocardial work in HFrEF patients with RBBB. Nevertheless, these results await further confirmation by large-scale, multi-center randomized trials. Keywords: heart failure; cardiac resynchronization therapy; right bundle branch block; conduction system pacing; myocardial work and dyssynchrony 1. Introduction Cardiac resynchronization therapy (CRT) utilizing biventricular pacing (BVP) has been approved as an effective treatment for heart failure (HF) with reduced left ventricular (LV) ejection fraction (HFrEF), associated with significant intraventricular conduction delay. The most benefits after BVP can be expected in patients with a left bundle branch block (LBBB) pattern, while the improvement is less significant in the presence of a right bundle branch block (RBBB) morphology [1] . Conduction system pacing (CSP), including His bundle pacing (HBP) and left bundle branch area pacing (LBBAP), has recently emerged as an alternative to BVP to resynchronize the le

FAQs

What is the primary purpose of conduction system pacing in this study?

To assess echocardiographic and clinical outcomes of conduction system pacing in HFrEF patients with RBBB, focusing on cardiac functions, myocardial mechanics, energetics, and functional capacity.

How were patients selected for conduction system pacing?

Patients had RBBB, QRS duration ≥130 ms, LVEF <35%, and NYHA II–IV symptoms despite 6 months of optimized medical therapy, and CSP was attempted using His bundle pacing or left bundle branch area pacing as a primary strategy.

Which measured outcomes improved after CSP?

After CSP, QRS duration decreased, LVEF increased, global myocardial strain and myocardial work indices improved, NYHA class and 6-minute walk distance improved, and NT-proBNP decreased.

Sep 30, 2026

Upload by Blue Pony