Combined effects of high atrial septal pacing and reactive atrial antitachycardia pacing for reducing atrial fibrillation in sick sinus syndrome.

Background: It is unknown whether atrial fibrillation (AF) burden varies by pacing site in patients with reactive atrial antitachycardia pacing (rATP). We aimed to compare AF burden in patients with high atrial septal pacing (HASp) via delivery catheter and right atrial appendage pacing (RAAp) in patients with sick sinus syndrome (SSS).

Methods: We retrospectively identified 109 patients with a history of paroxysmal AF and SSS who had received dual-chamber pacemaker implantation between January 2017 and December 2019, of whom 39 and 70 patients had HASp and RAAp, respectively. rATP was initiated after a 1-month post-implantation run-in period.

Results: Patients with HASp had a significantly shorter P-wave duration during atrial pacing than those with RAAp (99.3 ± 10.4 vs. 116.0 ± 14.3 ms,  < .001). During the 3-year follow-up period, the incidence of an AF lasting longer than 1 or 7 days was significantly lower (hazard ratio [HR], 0.45;  = .016; HR, 0.24;  = .004) than in those with RAAp. The median time of AF/AT per day in the follow-up periods was significantly shorter in the HASp group than in the RAAp group (10 vs. 18 min/day,  = .018). Atrial lead division did not occur in the HASp group during the follow-up period.

Conclusions: HASp via delivery catheter is as safe as RAAp, and HASp combined with rATP is effective for reducing AF burden in patients with SSS and paroxysmal AF.