BACKGROUND: Left bundle branch pacing (LBBP) produces delayed, unphysiological activation of the right ventricle. Using ultra-high-frequency electrocardiography (UHF-ECG), we explored how bipolar anodal septal pacing with direct LBB capture (aLBBP) affects the resultant ventricular depolarization pattern. METHODS: In patients with bradycardia, His bundle pacing (HBP), unipolar nonselective LBBP (nsLBBP), aLBBP, and right ventricular septal pacing (RVSP) were performed. Timing of local ventricular activation, in leads V1-V8, was displayed using UHF-ECG, and electrical dyssynchrony (e-DYS) was calculated as the difference between the first and last activation. Durations of local depolarizations were determined as the width of the UHF-QRS complex at 50% of its amplitude. RESULTS: aLBBP was feasible in 63 of 75 consecutive patients with successful nsLBBP. aLBBP significantly improved ventricular dyssynchrony (mean -9 ms; 95% CI (-12;-6) vs. -24 ms (-27;-21), ), p < 0.001) and shortened local depolarization durations in V1-V4 (mean differences -7 ms to -5 ms (-11;-1), p < 0.05) compared to nsLBBP. aLBBP resulted in e-DYS -9 ms (-12; -6) vs. e-DYS 10 ms (7;14), p < 0.001 during HBP. Local depolarization durations in V1-V2 during aLBBP were longer than HBP (differences 5-9 ms (1;14), p < 0.05, with local depolarization duration in V1 during aLBBP being the same as during RVSP (difference 2 ms (-2;6), p = 0.52). CONCLUSION: Although aLBBP improved ventricular synchrony and depolarization duration of the septum and RV compared to unipolar nsLBBP, the resultant ventricular depolarization was still less physiological than during HBP.

1st Department of Cardiology Interventional Electrocardiology and Hypertension Jagiellonian University Medical College Krakow Poland

Cardiocenter 3rd Faculty of Medicine Charles University and University Hospital Kralovske Vinohrady Prague Czech Republic

Department of Anesthesia and Intensive Care Charles University and University Hospital Kralovske Vinohrady Prague Czech Republic

Department of Physiology Cardiovascular Research Institute Maastricht Maastricht University Maastricht Netherlands

Faculty of Electrical Engineering and Communication Department of Biomedical Engineering Brno University of Technology Brno Czech Republic

Institute of Scientific Instruments The Czech Academy of Sciences Brno Czech Republic

International Clinical Research Center St Anne's University Hospital Brno Czech Republic

See more in PubMed

Su L, Wang S, Wu S, Xu L, Huang Z, Chen X, et al. Long-Term safety and feasibility of left bundle branch pacing in a large single-center study. Circ Arrhythm Electrophysiol. (2021) 14(2):e009261. 10.1161/CIRCEP.120.009261 PubMed DOI

Curila K, Jurak P, Jastrzebski M, Prinzen F, Waldauf P, Halamek J, et al. Left bundle branch pacing compared to left ventricular septal myocardial pacing increases interventricular dyssynchrony but accelerates left ventricular lateral wall depolarization. Heart Rhythm. (2021) 18(8):1281–9. 10.1016/j.hrthm.2021.04.025 PubMed DOI

Huang W, Chen X, Su L, Wu S, Xia X, Vijayaraman P. A beginner's guide to permanent left bundle branch pacing. Heart Rhythm. (2019) 16(12):1791–6. 10.1016/j.hrthm.2019.06.016 PubMed DOI

Lin J, Chen K, Dai Y, Sun Q, Li Y, Jiang Y, et al. Bilateral bundle branch area pacing to achieve physiological conduction system activation. Circ Arrhythm Electrophysiol. (2020) 13(8):e008267. 10.1161/CIRCEP.119.008267 PubMed DOI

Wu H, Jiang L, Shen J, Zhang L, Zhong J, Zhuo S. Electrophysiological characteristics and possible mechanism of bipolar pacing in left bundle branch pacing. Heart Rhythm. (2022) 19(12):2019–26. 10.1016/j.hrthm.2022.06.022 PubMed DOI

Vijayaraman P, Dandamudi G, Zanon F, Sharma PS, Tung R, Huang W, et al. Permanent his bundle pacing: recommendations from a multicenter his bundle pacing collaborative working group for standardization of definitions, implant measurements, and follow-up. Heart Rhythm. (2018) 15(3):460–8. 10.1016/j.hrthm.2017.10.039 PubMed DOI

Liu X, Niu HX, Gu M, Chen X, Hu Y, Cai M, et al. Contrast-enhanced image-guided lead deployment for left bundle branch pacing. Heart Rhythm. (2021) 18(8):1318–25. 10.1016/j.hrthm.2021.04.015 PubMed DOI

Jastrzebski M, Kielbasa 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):4161–73. 10.1093/eurheartj/ehac445 PubMed DOI PMC

Jurak P, Curila K, Leinveber P, Prinzen FW, Viscor I, Plesinger F, et al. Novel ultra-high-frequency electrocardiogram tool for the description of the ventricular depolarization pattern before and during cardiac resynchronization. J Cardiovasc Electrophysiol. (2020) 31(1):300–7. 10.1111/jce.14299 PubMed DOI

Curila K, Jurak P, Vernooy K, Jastrzebski M, Waldauf P, Prinzen F, et al. Left ventricular myocardial septal pacing in close proximity to LBB does not prolong the duration of the left ventricular lateral wall depolarization compared to LBB pacing. Front Cardiovasc Med. (2021) 8:787414. 10.3389/fcvm.2021.787414 PubMed DOI PMC

Li Y, Chen K, Dai Y, Li C, Sun Q, Chen R, et al. Left bundle branch pacing for symptomatic bradycardia: implant success rate, safety, and pacing characteristics. Heart Rhythm. (2019) 16(12):1758–65. 10.1016/j.hrthm.2019.05.014 PubMed DOI

Sharma PS, Patel NR, Ravi V, Zalavadia DV, Dommaraju S, Garg V, et al. Clinical outcomes of left bundle branch area pacing compared to right ventricular pacing: results from the geisinger-rush conduction system pacing registry. Heart Rhythm. (2022) 19(1):3–11. 10.1016/j.hrthm.2021.08.033 PubMed DOI

Stephenson RS, Atkinson A, Kottas P, Perde F, Jafarzadeh F, Bateman M, et al. High resolution 3-dimensional imaging of the human cardiac conduction system from microanatomy to mathematical modeling. Sci Rep. (2017) 7(1):7188. 10.1038/s41598-017-07694-8 PubMed DOI PMC

Assessment of ventricular electrical heterogeneity in left bundle branch pacing and left ventricular septal pacing by using various electrophysiological methods

Ventricular dyssynchrony imaging, echocardiographic and clinical outcomes of left bundle branch pacing and biventricular pacing

Ultra-High-Frequency ECG in Cardiac Pacing and Cardiac Resynchronization Therapy: From Technical Concept to Clinical Application