Short-term safety and feasibility of a practical approach to combined atrial and ventricular physiological pacing: An initial single-center experience

Abstract

Background: Traditional right atrial appendage (RAA) pacing accentuates conduction disturbances as opposed to Bachmann bundle pacing (BBP).

Objective: The purpose of this study was to evaluate the feasibility, efficacy, and safety of routine anatomically guided high right atrial septal (HRAS) pacing with activation of Bachmann bundle combined with routine left bundle branch area pacing (LBBAP).

Methods: This retrospective single-center study included 96 consecutive patients who underwent 1 of 2 strategies: physiological pacing (PP) (n = 32) with HRAS and LBBAP leads and conventional pacing (CP) (n = 64) with traditional RAA and right ventricular apical leads. Baseline characteristics, sensing, pacing thresholds, and impedances were recorded at implantation and follow-up.

Results: The PP and CP cohorts were of similar age (74.2 ± 13.8 years vs 73.9 ± 9.9 years) and sex (28.1% vs 40.6% female). There were no differences in procedural time (95.0 ± 31.4 minutes vs 86.5 ± 33.3 minutes; P = .19) or fluoroscopy time (12.1 ± 4.5 minutes vs 12.3 ± 13.5 minutes; P = .89) between cohorts. After excluding patients who received >2 leads, these parameters became significantly shorter in the CP cohort. The PP cohort exhibited higher atrial pacing thresholds (1.5 ± 1.1 mV vs 0.8 ± 0.3 mV; P <.001) and lower p waves (1.8 ± 0.8 mV vs 3.8 ± 2.3 mV; P <.001) at implantation and at follow-up. In the PP cohort, 72% of implants met criteria for BBP; of the ventricular leads, 94% demonstrated evidence of LBBAP. One lead-related complication occurred in each cohort.

Conclusion: Routine placement of leads in the HRAS is a feasible and safe alternative to standard RAA pacing, allowing for BBP in 72% of patients. HRAS pacing can be combined with LBBAP as a routine strategy.

Keywords: Atrialmyocardium; Bachmann bundle; Interatrial septum; Interventricular septum; Left bundle; Pacing; Right atrial appendage.

Figure 1

High right atrial septal anatomy. A: Electroanatomic maps of right atrium and left atrium (LA) seen in the left anterior oblique (LAO) projection. White dotted line outlines the high right atrial septum. Yellow dotted line represents the endocardial border of the septal LA. B:White dotted line corresponds to the septal aspect of the contrast-filled superior vena cava (SVC)–right atrial junction seen in LAO projection. The typical target site for lead fixation is the mid-portion (∗) or just below this along the white dotted line. C: The epicardial structure overlying this region is where the Bachmann bundle is located and is highlighted by the yellow box. Atlas of Cardiac Anatomy, Digital Edition © 2022 Shumpei Mori, Kalyanam Shivkumar. IVC = inferior vena cava; LIPV = left inferior pulmonary vein; LSPV = left superior pulmonary vein.

Figure 2

P-wave characteristics of Bachmann bundle pacing. A: Sinus rhythm and high right atrial paced rhythm from a patient in the high right atrial septal pacing cohort who met all criteria for Bachmann bundle pacing. Note the tall and narrow P waves best appreciated in the inferior leads. B, C: Chest radiographs in posteroanterior (B) and lateral (C) views showing atrial lead position in the same patient and the ventricular lead in the typical position for left bundle branch area pacing.

Figure 3

Mean pacing threshold (top), P-wave amplitude (sensing) (middle), and bipolar impedance (bottom) values of the physiological pacing (PP) and conventional pacing (CP) cohorts at 3 follow-up points: day of implant, first postoperative day (POD-1), and final follow-up. Blue denotes PP cohort; orange denotes CP cohort.