Properties during implant and the presence of transitions to confirm capture of Bachmann's Bundle
M Erickson, N Tomassoni, R Sun, F A Subzposh, A Batul, P VijayaramanAbstract
Background/Introduction
Bachmann bundle pacing (BBP) has emerged as a favorable alternative to traditional right atrial appendage (RAA) pacing, offering benefits such as reduced atrial fibrillation and improved diastolic function. These advantages are realized only when the lead effectively captures Bachmann’s bundle. Historically, implant techniques have relied on fluoroscopy and unipolar mapping for guidance.
Purpose
This study presents a dataset of serial Bachmann bundle lead implants in a general population. We describe several transition patterns observed with decremental output and outline the properties of selective Bachmann pacing. Our aim is to provide a foundation for future research in this area.
Methods
This non-randomized observational study included serial patients undergoing device implantation requiring an atrial lead from April 2024 through July 2025. During implantation, the Bachmann region was mapped in a bipolar configuration. As the sheath was advanced down the SVC, local right atrial (RA) and Bachmann bundle signals overlapped, and implantation was performed in this region. Decremental output revealed transitions from non-selective Bachmann’s capture to either selective Bachmann’s capture or local RA capture. Demographics, medical history, procedural details, echocardiographic data pre- and post-implant, and implant properties were recorded, including double potential interval, isoelectric segment duration, P-wave duration, PR intervals pre- and post-implant, and P-wave axis pre- and post-implant. Long-term follow-up data were also collected.
Results
Out of 136 patients we were able to successfully implant 130 leads (95%). In 12(*9%) lead was implanted during an arrhythmia, and we were unable to assess for transitions. Of the 118 successful implants in sinus rhythm, 108(91%) had transitions, with 85(79%) being NS to sel, 23(21%) being NS to RA-capture. 10 Patients with no transition were non-selective until loss of capture. 45 patients had normal interatrial conduction, 58 patients had partial interatrial block, and 17 patients had complete interatrial block. Across all successful implants the mean reduction in p-wave duration was 11ms. With selective Bachmann bundle pacing, the mean p-wave reduction was 20ms. The mean PR interval prior to implant was 205ms, in patients with a NS-Sel transition the mean PR interval was 220ms at high output, and 232ms at low output, in patients with a NS-RA transition, the PR interval was 225ms at high output, and 239ms at low output. Leads were stable over long term follow up. There was 1 atrial lead dislodgment, and 1 pocket hematoma.
Conclusion
Implanting Bachmann’s bundle leads is safe and feasible across all patient populations. The presence of transitions can assist in confirming Bachmann’s bundle capture.