Obstructive respiratory events and premature atrial contractions after cardioversion

Recurrence of atrial fibrillation (AF) after electrical cardioversion (ECV) is increased in patients with obstructive sleep apnoea (OSA). In patients with persistent AF, with (n=40) and without (n=32) obstructive respiratory events (OREs) during sedation for ECV, we determined the occurrence of premature atrial contractions (PACs) before and after insertion of a nasopharyngeal tube. The influence of acute obstructive respiratory events on atrial electrophysiology after termination of AF was studied in pigs. Incidence of PACs directly after ECV was higher in patients with OREs compared to those without OREs (7±2 versus 1±1 per 10 s, respectively; p<0.01). Occurrence of PACs could be reduced by 79% by insertion of a nasopharyngeal tube. In a subsequent sleeping study, patients with OREs had higher apnoea-hypopnoea indices and more PACs during night. 16 patient with and four patients without OREs had a relapse of AF during 1 week after ECV (p<0.01). In pigs, acute OREs after 30 min of AF increased occurrence of PACs and vulnerability for reinduction of AF, which could be attenuated by atropine, beta-blockers and renal denervation. OREs are associated with increased occurrence of PACs and more early relapse of AF. OREs increase occurrence of PACs and vulnerability for reinduction of AF by sympathovagal imbalance.