Electrophysiological characterization of the Bachmann bundle region using 3D electroanatomical mapping and peak...

Physiological pacing of the atrium, specifically targeting the Bachmann bundle area (BBA), has been associated with improved interatrial conduction and reduced atrial arrhythmia risk. The Bachmann bundle (BB) is the principal interatrial conduction tract, yet its electrophysiological definition in humans remains incompletely characterized. This study aimed to describe the electrogram features of the BBA using 3D electroanatomical-mapping (EAM) with peak-frequency (PF) analysis during atrial lead implantation.

All patients undergoing dual-chamber pacemaker implantation with the atrial lead positioned in the BBA were included. Right atrial mapping was performed using either a quadripolar or the HD Grid catheter. PF maps were created and PFs at the targeted site were measured before and after lead positioning. Procedural parameters, P-wave duration (PWD) and pacing thresholds were analyzed.

Twelve consecutive patients undergoing dual-chamber pacemaker implantation with the atrial lead positioned in the (BBA) were prospectively studied. The optimal PF band for BBA localization was 400-500 Hz (AUC = 0.83, sensitivity 87%, specificity 80%). Lead fixation was associated with a reproducible PF decrease, which correlated with P-wave shortening (r = -0.66, p = 0.02). Lower PF values (< 400 Hz) after lead fixation were associated with effective P-wave narrowing. No complications occurred. At three-month follow-up, all leads remained stable with normal pacing parameters.

This study provides a characterization of the human Bachmann bundle region using 3D mapping. High PF electrograms distinguish the BBA from adjacent atrial tissue, while PF reductions during fixation correlate with improved P-wave shortening.