Severe device-detected sleep apnea is associated with increased ventricular pacing in sinus node dysfunction

Background Minimizing ventricular pacing (VP) is essential in sinus node dysfunction (SND). Sleep apnea causes autonomic fluctuations that may induce transient atrioventricular (AV) block. Purpose To determine whether severe device-detected sleep apnea (DDSA) is associated with transient increases in VP among patients with SND and preserved atrioventricular conduction. Methods Continuous daily pacemaker data from the prospective ACaSA study were analysed. Patients with SND and preserved AV conduction were dynamically censored to exclude sustained conduction impairment. Severe DDSA was defined as respiratory disturbance index (RDI) ≥20 events/h. Mixed-effects models assessed associations between severe DDSA and breakthrough VP (>1%) and VP intensity, adjusted for age, sex, body mass index, and beta-blocker use. State-transition analyses evaluated reversibility and washout, and reverse-direction analyses tested whether breakthrough VP was associated with next-night DDSA. Results Eighty-seven patients contributed 33,464 nights. Severe DDSA was associated with higher odds of breakthrough VP (adjusted odds ratio [aOR] 1.46; 95% confidence interval [CI] 1.27–1.69; p<0.001). Absolute risk increased from 6.0% to 7.9% (+32%). VP burden was higher following severe DDSA nights (1.20% vs 0.54%; p<0.001). Risk peaked during consecutive severe nights (aOR 1.97; 95% CI 1.60–2.43), persisted through recovery Day 2, and normalized by Day 4. Breakthrough VP was associated with increased odds of severe DDSA on the subsequent night (aOR 1.31; 95% CI 1.12–1.54). Conclusion In SND patients with preserved AV conduction, severe DDSA is associated with transient, reversible breakthrough VP, consistent with a functional autonomic mechanism.Abstract