The Bachmann Bundle Pacing Target: Retrograde Mapping and Microstructural Correlation.

Electroanatomic mapping of the right atrial breakout site during retrograde Bachmann bundle pacing in 15 patients in sinus rhythm undergoing pulmonary vein isolation provided the anatomic localization of the putative lead insertion target for Bachmann bundle pacing. In all patients the target area could be mapped to the inferoseptal superior vena cava, with some variation in the earliest breakout site in the anteroposterior plane. Microstructural correlation reveals that the Bachmann bundle functions as an atrial conduction pathway supported by anatomic features to provide interatrial synchrony.