Clinical/Electrophysiological Characteristics of Infra-Nodal Wenckebach in Patients with Indication for Permanent Ventricular Pacing: A Prospective Study

Anindya Ghosh; Deep Chandh C Raja; Nitish Badhwar; Chenni S Sriram; Ulhas M Pandurangi

doi:10.1016/j.hrthm.2024.05.017

Clinical/Electrophysiological Characteristics of Infra-Nodal Wenckebach in Patients with Indication for Permanent Ventricular Pacing: A Prospective Study

Heart Rhythm. 2024 May 13:S1547-5271(24)02559-1. doi: 10.1016/j.hrthm.2024.05.017. Online ahead of print.

Authors

Anindya Ghosh¹, Deep Chandh C Raja², Nitish Badhwar³, Chenni S Sriram⁴, Ulhas M Pandurangi⁵

Affiliations

¹ Department of Cardiac Electrophysiology and Pacing, Arrhythmia Heart Failure Academy, The Madras Medical Mission, Chennai, Tamil Nadu, India.
² Department of Cardiac Electrophysiology and Pacing, Kauvery Hospital, Chennai.
³ Stanford University School of Medicine, California, USA.
⁴ Division of Cardiology, Sub-section of Electrophysiology, Children's Hospital of Michigan and Detroit Medical Center, Detroit, MI, USA.
⁵ Department of Cardiac Electrophysiology and Pacing, Arrhythmia Heart Failure Academy, The Madras Medical Mission, Chennai, Tamil Nadu, India. Electronic address: arrhythmiaheartfailureacademy@gmail.com.

PMID: 38750913
DOI: 10.1016/j.hrthm.2024.05.017

Abstract

Background: Infra-nodal Wenckebach is rare and is not well characterized.

Objectives: We prospectively studied clinical and electrophysiological characteristics of patients with atrioventricular (AV) Wenckebach with an indication for permanent ventricular pacing.

Methods: Over a 2-year-period, all subjects with an indication for permanent ventricular pacing underwent targeted pre-implant electrophysiological study. Clinical/electrophysiologic characteristics at presentation and ventricular pacing percentage at 6-month follow-up were evaluated.

Results: A total of 163 patients [median age 68 (IQR 60-74) years, male 59%, median QRS duration 110 (90-130) ms, complete AV block in 123 (69.3%)] were included. AV Wenckebach was noted in 22 (13.4%) patients [median age 70 (63-76.5) years, male 54%, median QRS duration 120 (110-140) ms] and classified as infra-nodal (12/163 or 7.3%) vs. AV nodal (10/163 or 6.1%). Patients with infra-nodal Wenckebach (Infra-His in all), when compared to AV nodal Wenckebach, demonstrated higher frequency with LVEF <40% (41.7% vs. 0%, p=0.04), longer median HV interval (90 vs. 49 ms, p=0.005), lower frequency of isolated 1^st degree AV block (8.3% vs. 60%, p=0.002), higher frequency of right bundle branch block with left-anterior fascicular block (75% vs. 10%, p=0.02), lesser PR increment at onset of AVW (20.5 vs. 80 ms, p=0.002), and onset of 2:1 AV block at longer cycle lengths (91.7% vs. 20%, p=0.002).

Conclusions: Among patients referred for pacemaker implantation, infra-nodal Wenckebach was present in 27.5% (11/40) of patients without complete AV block. It was as frequent as AV nodal Wenckebach and associated with characteristic electrophysiologic findings.

Keywords: Atrioventricular block; Electrophysiological characteristics; Infra-Hisian; Infra-nodal; Wenckebach.