The Dynamic Relationship Among Atrial Pacing, Premature Atrial Beats, Mode Switching, and Atrial High-Rate Episodes in Patients with Sick Sinus Syndrome

Objectives: This study aimed to explore the association between atrial pacing percentage, frequency of premature atrial beats, and mode-switch episodes and the occurrence of atrial high-rate episodes (AHREs) in patients with sick sinus syndrome (SSS) who underwent dual-chamber pacemaker (DDDR) implantation. Materials and Methods:This prospective, single-center, observational study included 60 patients with SSS and Medtronic DDDR pacemakers.Patients with pre-existing atrial fibrillation, ischemic stroke, heart failure, chronic renal failure, or insufficient follow-up data were excluded.Key parameters, such as atrial pacing percentage, premature atrial beats, mode-switch episodes, and AHREs, were evaluated at 1, 3, and 6 months and at 1 and 2 years after implantation. Results:The mean age of the participants was 65.5 years, with 53.3% of them being male.During the first 3 months, atrial pacing percentage showed an inverse correlation with AHREs (83.719.8% at 1 month and 85.219.9% at 3 months; p=0.026 and p=0.046, respectively).mode-switch episodes and premature atrial beats were significantly associated with AHREs within the first 6 months (mode-switch episodes: 11.24.3 at 1 month, 11.43.2 at 3 months, and 6.73.