Cardioversion of atrial fibrillation or atrial flutter into sinus rhythm reduces nocturnal central respiratory events and unmasks obstructive sleep apnoea.

AIMS: Sleep-disordered breathing (SDB), in particular obstructive sleep apnoea, is associated with an increased risk of onset or recurrence of atrial fibrillation (AF) and atrial flutter. This prospective study investigated the relationship between restoration of sinus rhythm and SDB in patients with AF or atrial flutter.

METHODS AND

RESULTS

138 consecutive patients (age 67.8 ± 10.3 years, 67.4 % male) with AF (86.2 %) or atrial flutter (13.8 %) were enrolled and underwent multichannel cardiorespiratory polygraphy the night before and immediately after electrical cardioversion (CV). None of the patients was treated with ventilation therapy before or during the study. Overall prevalence of SDB [apnoea-hypopnoea index (AHI) ≥5/h] was 92 % and prevalence of moderate-to-severe SDB (AHI) ≥15/h was 64 %. Within the first night after CV, AHI decreased from 23.4 ± 16.3 to 16.3 ± 11.5/h, p < 0.001. This was due to a significant decrease in central respiratory events, with a total reduction of patients showing central sleep apnoea (n = 53 at baseline vs n = 23 immediately after CV; p < 0.001).

CONCLUSIONS

In conclusion, SDB represents a highly prevalent comorbidity in patients with atrial arrhythmias. Through cardioversion, an immediate reduction of SDB can be detected due to a significant reduction in central respiratory events.