841Multi-center clinical experience with the usage of implantable pulse generators for permanent his bundle pacing
Authors: Dinerman J , Deshmukh P , Qiao J , Li W , Mangual J , Brenyo A , Zanon F , Calo L , Thibault B 
Published: June 2020

Abstract

Funding Acknowledgements
Abbott

Introduction
His Bundle pacing (HBP) offers a more physiologic pacing approach to maintain electrical synchrony. Permanent HBP has emerged as a feasible and safe alternative to traditional pacemaker therapy and cardiac resynchronization therapy (CRT) with clinical and electrophysiological advantages. However, traditional implantable pulse generators (IPGs) have been used for HBP without supporting algorithms developed for HBP.

Objective
To assess a multi-center clinical experience with the usage of IPGs for permanent HBP and to identify the needs for HBP specific device algorithms.

Methods
Patients from 6 centers worldwide with a permanent HBP lead and an existing Abbott pacemaker, defibrillator, or CRT device were enrolled in this study. Device data and 12-lead surface ECG were collected simultaneously during device interrogation at a follow-up visit. HBP capture types at different pacing amplitudes were adjudicated using 12-lead ECG. Bundle branch block (BBB) correction by HBP was defined as QRS duration ≤130 ms or narrowing by &gt;20%. Amplitudes of atrial and ventricular components on the HBP lead from both unipolar and bipolar sensing configurations were measured. Amplitudes of atrial component ≥ 0.5 mV on HB sensing EGMs were measured and considered as having risk of atrial oversensing.

Results
A total of 133 patients (75 ± 10 yrs, 92 male) were enrolled and completed study data collection post implant (median: 48, range: 0-3110 days). Patient characteristics, IPG type, and HBP lead connections were shown in the table. Dual-chamber pacemaker with HBP lead connected to V port was the most popular (65%) configuration. In non-BBB patients, pacing thresholds for selective HB (n = 44), non-selective HB (n = 54), and myocardial capture (n = 21) were 1.5 ± 1.2, 2.9 ± 2.0, 1.4 ± 1.5 V, respectively, at pulse width of 0.8 ± 0.4 ms. In BBB patients, LBBB and RBBB were corrected in 10/23 (43%) and 12/27 (44%) patients with pacing thresholds of 3.5 ± 2.4 and 2.1 ± 2.0 V, respectively, at pulse width of 0.8 ± 0.3 ms. AutoCapture™ algorithm was tested in 63 patients and recommended to be OFF in 28 (44%) patients. EGMs during intrinsic AV conduction were collected in 86 patients. A risk of atrial oversensing was identified in 24 (28%) and 27 (31%) patients during bipolar and unipolar sensing, respectively, and in 17 (20%) patients during both configurations. The average amplitude of the atrial and ventricular components on the HB lead EGM were 2.1 ± 2 and 6.0 ± 5.8 mV during bipolar sensing and 1.3 ± 1.2 and 6.3 ± 6.5 mV during unipolar sensing, respectively. Five (6%) patients had A/V amplitude ratios higher than 1.

Conclusions
Currently, various device configurations are used to overcome the fact that IPGs are not designed for HBP. Additionally, HBP presents unique challenges to ensure appropriate capture and sensing beyond traditional RV pacing. HBP specific device algorithms are needed to ensure correct IPG usage and facilitate device programming.
Abstract Figure.