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

Tóth, Anna Zsófia; Nagy, László; Jenei, Csaba; Ráduly, Arnold Péter; Sándorfi, Gábor; Szabó, Krisztina Mária; Kiss, Alexandra; Nagy, László Tibor; Szilágyi, Gergő István; Csanádi, Zoltán

doi:10.3390/jcm15010232

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

by

Anna Zsófia Tóth

^†,

László Nagy

^*,†,

Csaba Jenei

,

Arnold Péter Ráduly

,

Gábor Sándorfi

,

Krisztina Mária Szabó

,

Alexandra Kiss

,

László Tibor Nagy

,

Gergő István Szilágyi

and

Zoltán Csanádi

Division of Cardiology, Department of Cardiology, Faculty of Medicine, University of Debrecen, Móricz Zsigmond krt. 22., H-4032 Debrecen, Hungary

^*

Author to whom correspondence should be addressed.

^†

These authors contributed equally to this work.

J. Clin. Med. 2026, 15(1), 232; https://doi.org/10.3390/jcm15010232 (registering DOI)

Submission received: 2 December 2025 / Revised: 22 December 2025 / Accepted: 25 December 2025 / Published: 27 December 2025

(This article belongs to the Special Issue Advances in Arrhythmia Diagnosis and Management)

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Abstract

Background/Objectives: Conduction system pacing (CSP) is a potential alternative to biventricular 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

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MDPI and ACS Style

Tóth, A.Z.; Nagy, L.; Jenei, C.; Ráduly, A.P.; Sándorfi, G.; Szabó, K.M.; Kiss, A.; Nagy, L.T.; Szilágyi, G.I.; Csanádi, Z. Conduction System Pacing Improved Cardiac Functions, Myocardial Work and Functional Capacity in Heart Failure with Reduced Ejection Fraction and Right Bundle Branch Block. J. Clin. Med. 2026, 15, 232. https://doi.org/10.3390/jcm15010232

AMA Style

Tóth AZ, Nagy L, Jenei C, Ráduly AP, Sándorfi G, Szabó KM, Kiss A, Nagy LT, Szilágyi GI, Csanádi Z. Conduction System Pacing Improved Cardiac Functions, Myocardial Work and Functional Capacity in Heart Failure with Reduced Ejection Fraction and Right Bundle Branch Block. Journal of Clinical Medicine. 2026; 15(1):232. https://doi.org/10.3390/jcm15010232

Chicago/Turabian Style

Tóth, Anna Zsófia, László Nagy, Csaba Jenei, Arnold Péter Ráduly, Gábor Sándorfi, Krisztina Mária Szabó, Alexandra Kiss, László Tibor Nagy, Gergő István Szilágyi, and Zoltán Csanádi. 2026. "Conduction System Pacing Improved Cardiac Functions, Myocardial Work and Functional Capacity in Heart Failure with Reduced Ejection Fraction and Right Bundle Branch Block" Journal of Clinical Medicine 15, no. 1: 232. https://doi.org/10.3390/jcm15010232

APA Style

Tóth, A. Z., Nagy, L., Jenei, C., Ráduly, A. P., Sándorfi, G., Szabó, K. M., Kiss, A., Nagy, L. T., Szilágyi, G. I., & Csanádi, Z. (2026). Conduction System Pacing Improved Cardiac Functions, Myocardial Work and Functional Capacity in Heart Failure with Reduced Ejection Fraction and Right Bundle Branch Block. Journal of Clinical Medicine, 15(1), 232. https://doi.org/10.3390/jcm15010232

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

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