Leadless Atrial Pacing Targeting Bachmann Bundle for Atrial Resynchronization: A Single Center Registry

Interatrial conduction delay (IACD) resulting from fibrosis or functional block in Bachmann bundle (BB) occurs often in patients with sinus node dysfunction (SND) and increases the risk of atrial fibrillation (AF). Pacing the BB in patients with SND may reduce AF burden. Little is known of the feasibility and effectiveness of BB leadless atrial pacemaker (BBLAP) implantation.

To determine if BBLAP is safe, feasible and improves IACD.

This registry prospectively enrolled 21 consecutive adults with baseline P wave duration (PWD) >120ms undergoing BBLAP for SND. Fluoroscopy, intracardiac echocardiography and left atrial conduction time (LACT) measurements from a decapolar coronary sinus (CS) catheter were used to facilitate implantation. BBLAP implant success was defined as improved PWD, P wave morphology, and LACT. Baseline and BBLAP LACT and PWD, axis, and morphology were compared.

Of the 21 patients enrolled, 17 had successful BBLAP (81%). Among those with successful BBLAP, baseline PWD was 150 (±21) ms, BBLAP PWD was 113 (±23) ms, a reduction of 37 (±13) ms, p < 0.001. BBLAP P wave axis was inferiorly directed in all cases. 8/8 patients with a negative terminal P wave in the inferior leads at baseline had correction with BBLAP. LACT decreased from 113 (±35) ms to 78 (±33) ms, mean difference 35 (±15) ms, p <0.001, with BBLAP. 13/17 patients demonstrated a shift in CS activation from proximal-distal activation to mid- or distal-proximal activation during BBLAP. In all cases there were no complications.

The BBLAP implant technique presented in this registry is feasible and reduced IACD. Further study on the effect of BBLAP on AF burden is needed.