Long-term outcomes of single atrial lead pacing in sick sinus syndrome: risk stratification using wenckebach block rate
A Takami, M Kato, F Hirano, Y Kotake, M HatanoAbstract
Background/Introduction
In patients with sick sinus syndrome (SSS), concerns about long-term atrioventricular (AV) conduction stability have led to frequent dual-chamber implantation. Although single atrial lead pacing (AAI pacing) is considered safe, prior studies were limited by short follow-up and prophylactic ventricular lead use, leaving long-term natural history uncertain. Contemporary pacing strategies emphasize avoiding unnecessary ventricular pacing and lead-related complications, underscoring the importance of clarifying the long-term need for ventricular lead addition.
Purpose
We sought to define the long-term natural history of AV conduction after AAI pacing and evaluate the prognostic value of baseline Wenckebach block rate (WBR).
Methods
We retrospectively analyzed 142 consecutive symptomatic SSS patients who underwent electrophysiological study and received AAI pacing between 1991 and 2010. Patients with preserved AV conduction and baseline WBR ≥100 bpm were stratified by a pre-specified 130 bpm cut-off. The primary endpoint was ventricular lead addition for bradyarrhythmia.
Results
Median follow-up was 206 months (IQR 114–246), and 97 patients (68%) were followed until death. Ventricular lead addition occurred in 10 patients (0.45 per 100 person-years). Kaplan–Meier analysis showed a lower incidence in patients with WBR ≥130 bpm than in those with WBR <130 bpm (log-rank p=0.002). Baseline WBR predicted ventricular lead addition and provided clinically useful risk stratification (AUC 0.78).
Conclusions
Over extended follow-up, ventricular lead addition was rarely required after AAI pacing in SSS patients with preserved AV conduction. Baseline WBR enables long-term risk stratification and may help guide pacing strategy.