Physiologic Pacing in 2025: Guidance Made Simple
DOI:
https://doi.org/10.58931/cct.2025.1210Abstract
Conventional right ventricular pacing (RVP), particularly at the right ventricular apex, has long been the standard approach for ventricular pacing in patients requiring permanent pacemakers. However, RVP has been shown to introduce electrical and mechanical dyssynchrony, resulting in adverse remodelling, atrial fibrillation, and heart failure. The deleterious effects of a high RVP burden have been demonstrated in the MOST and DAVID trials, wherein patients with ventricular pacing >40% were identified as being at risk of increased adverse clinical outcomes, such as hospitalization for heart failure and death (hazard ratio [HR] 1.61; 95% confidence interval [CI] 1.06–2.44).
In patients with baseline ventricular systolic dysfunction and left bundle branch block or a high ventricular pacing burden, cardiac resynchronization therapy (CRT) using conventional biventricular pacing (BiVP) has been shown to be superior to RVP in preventing ventricular dilation, hospitalization for heart failure, and death. Both the BLOCK-HF trial, which compared BiVP to RV pacing in patients with a left ventricular ejection fraction (LVEF) ≤50% and a high pacing burden, and the MADIT-CRT trial, which compared implantable cardioverter-defibrillator therapy alone to CRT with defibrillator in patients with LVEF ≤30% and QRS duration ≥130ms, showed a reduction in all-cause mortality and heart failure events in the BiVP group (HR 0.74; 95% CI 0.60–0.90 and HR 0.66; 95% CI 0.52–0.84, respectively). However, approximately one-third of patients do not respond to conventional BiVP. Moreover, the benefits of conventional BiVP have not been consistently shown across all cohorts.
To overcome the detrimental effects of RVP and the limitations of conventional BiVP, conduction system pacing (CSP) was introduced. This approach harnesses the His-Purkinje system, thereby delivering stimulation mimicking native ventricular activation. The two primary CSP techniques, His bundle pacing (HBP) and left bundle branch area pacing (LBBAP), have demonstrated promise in improving both electrical synchrony and clinical outcomes.
References
Sweeney MO, Hellkamp AS, Ellenbogen KA, Greenspon AJ, Freedman RA, Lee KL, et al. Adverse effect of ventricular pacing on heart failure and atrial fibrillation among patients with normal baseline QRS duration in a clinical trial of pacemaker therapy for sinus node dysfunction. Circulation. 2003;107(23):2932–2937. doi:10.1161/01.CIR.0000072769.17295.B1 DOI: https://doi.org/10.1161/01.CIR.0000072769.17295.B1
Sharma AD, Rizo-Patron C, Hallstrom AP, O’Neill GP, Rothbart S, Martins JB, et al. Percent right ventricular pacing predicts outcomes in the DAVID trial. Heart Rhythm. 2005;2(8):830–834. doi:10.1016/j.hrthm.2005.05.015 DOI: https://doi.org/10.1016/j.hrthm.2005.05.015
Curtis AB. Biventricular pacing for atrioventricular block and systolic dysfunction. N Engl J Med. 2013;369(6):579. doi:10.1056/NEJMc1306998 DOI: https://doi.org/10.1056/NEJMc1306998
Moss AJ, Hall WJ, Cannom DS, Klein H, Brown MW, Daubert JP, et al. Cardiac-resynchronization therapy for the prevention of heart-failure events. N Engl J Med. 2009;361(14):1329–1338. doi:10.1056/NEJMoa0906431 DOI: https://doi.org/10.1056/NEJMoa0906431
Gerra L, Bonini N, Mei DA, Imberti JF, Vitolo M, Bucci T, et al. Cardiac resynchronization therapy (CRT) nonresponders in the contemporary era: A state-of-the-art review. Heart Rhythm. 2025;22(1):159-169. doi:10.1016/j.hrthm.2024.05.057 DOI: https://doi.org/10.1016/j.hrthm.2024.05.057
Tan ESJ, Soh R, Lee JY, et al. Clinical outcomes in conduction system pacing compared to right ventricular pacing in bradycardia. JACC Clin Electrophysiol. 2023;9(7 Pt 1):992-1001. doi:10.1016/j.jacep.2022.10.016
Curila K, Mizner J, Morava J, Smisek R, Vesela J, Sussenbek O, et al. Prospective randomized trial of conduction system pacing vs right ventricular pacing for patients with atrioventricular block; Prague CSP trial. Heart Rhythm. Published online May 22, 2025. doi:10.1016/j.hrthm.2025.05.036 DOI: https://doi.org/10.1016/j.hrthm.2025.05.036
Deshmukh P, Casavant DA, Romanyshyn M, Anderson K. Permanent, direct His-bundle pacing: a novel approach to cardiac pacing in patients with normal His-Purkinje activation. Circulation. 2000;101(8):869–877. doi:10.1161/01.cir.101.8.869 DOI: https://doi.org/10.1161/01.CIR.101.8.869
Huang W, Su L, Wu S, Xu L, Xiao F, Zhou X, et al. A novel pacing strategy with low and stable output: pacing the left bundle branch immediately beyond the conduction block. Can J Cardiol. 2017;33(12):1736.e1731–1736.e1733. doi:10.1016/j.cjca.2017.09.013 DOI: https://doi.org/10.1016/j.cjca.2017.09.013
Cabrera J, Anderson RH, Macías Y, Nevado-Medina J, Porta-Sánchez A, Rubio JM, et al. Variable arrangement of the atrioventricular conduction axis within the triangle of koch: implications for permanent his bundle pacing. JACC Clin Electrophysiol. 2020;6(4):362–377. doi:10.1016/j.jacep.2019.12.004 DOI: https://doi.org/10.1016/j.jacep.2019.12.004
Cabrera J, Anderson RH, Porta-Sánchez A, Macías Y, Cano Ó, Spicer DE, et al. The atrioventricular conduction axis and its implications for permanent pacing. Arrhythm Electrophysiol Rev. 2021;10(3):181–189. doi:10.15420/aer.2021.32 DOI: https://doi.org/10.15420/aer.2021.32
Jastrzębski M, Kiełbasa G, Cano O, Curila K, Heckman L, De Pooter J, et al. Left bundle branch area pacing outcomes: the multicentre European MELOS study. Eur Heart J. 2022;43(40):4161–4173. doi:10.1093/eurheartj/ehac445 DOI: https://doi.org/10.1093/eurheartj/ehac445
Burri H, Jastrzebski M, Cano Ó, Čurila K, de Pooter J, Huang W, et al. EHRA clinical consensus statement on conduction system pacing implantation: executive summary. Endorsed by the Asia-Pacific Heart Rhythm Society (APHRS), Canadian Heart Rhythm Society (CHRS) and Latin-American Heart Rhythm Society (LAHRS). Europace. 2023;25(4):1237–1248. doi:10.1093/europace/euad044 DOI: https://doi.org/10.1093/europace/euad044
Mirmaksudov M, Ross S, Kongsgård E, Edvardsen T. Enhancing cardiac pacing strategies: a review of conduction system pacing compared with right and biventricular pacing and their influence on myocardial function. Eur Heart J Cardiovasc Imaging. 2024;25(7):879–887. doi:10.1093/ehjci/jeae090 DOI: https://doi.org/10.1093/ehjci/jeae090
Tan ESJ, Soh R, Lee JY, Boey E, Ho KH, Aguirre S, et al. Clinical outcomes in conduction system pacing compared to right ventricular pacing in bradycardia. JACC Clin Electrophysiol. 2023;9(7 Pt 1):992–1001. doi:10.1016/j.jacep.2022.10.016 DOI: https://doi.org/10.1016/j.jacep.2022.10.016
Upadhyay GA, Vijayaraman P, Nayak HM, Verma N, Dandamudi G, Sharma PS, et al. His corrective pacing or biventricular pacing for cardiac resynchronization in heart failure. J Am Coll Cardiol. 2019;74(1):157–159. doi:10.1016/j.jacc.2019.04.026 DOI: https://doi.org/10.1016/j.jacc.2019.04.026
Vinther M, Risum N, Svendsen JH, Møgelvang R, Philbert BT. A randomized trial of His pacing versus biventricular pacing in symptomatic HF patients with left bundle branch block (His-alternative). JACC Clin Electrophysiol. 2021;7(11):1422–1432. doi:10.1016/j.jacep.2021.04.003 DOI: https://doi.org/10.1016/j.jacep.2021.04.003
Vijayaraman P, Ponnusamy S, Cano Ó, Sharma PS, Naperkowski A, Subsposh FA, et al. Left bundle branch area pacing for cardiac resynchronization therapy: results from the International LBBAP Collaborative Study Group. JACC Clin Electrophysiol. 2021;7(2):135–147. doi:10.1016/j.jacep.2020.08.015 DOI: https://doi.org/10.1016/j.jacep.2020.08.015
Vijayaraman P, Zanon F, Ponnusamy SS, Herweg B, Sharma P, Molina-Lerma M, et al. Conduction system pacing compared with biventricular pacing for cardiac resynchronization therapy in patients with heart failure and mildly reduced left ventricular ejection fraction: Results from International Collaborative LBBAP Study (I-CLAS) Group. Heart Rhythm. 2024. doi:10.1016/j.hrthm.2024.09.030 DOI: https://doi.org/10.1016/j.hrthm.2024.09.030
Vijayaraman P, Chelu MG, Curila K, Dandamudi G, Herweg B, Mori S, et al. Cardiac conduction system pacing: a comprehensive update. JACC Clin Electrophysiol. 2023;9(11):2358–2387. doi:10.1016/j.jacep.2023.06.005 DOI: https://doi.org/10.1016/j.jacep.2023.06.005

Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2025 Canadian Cardiology Today

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.