Cardiac arrhythmias in obstructive sleep apnea (from the Akershus Sleep Apnea Project).

Increased prevalence of cardiac arrhythmias has been reported in patients with severe obstructive sleep apnea (OSA), but this may not be generalizable to patients from the general population with a milder form of the condition. The aim of this study was to assess the association between cardiac arrhythmias and OSA of mainly mild and moderate severity. In total, 486 subjects (mean age 49 years, 55% men) recruited from a population-based study in Norway underwent polysomnography for OSA assessment and Holter recordings for arrhythmia assessment. Of these, 271 patients were diagnosed with OSA (apnea-hypopnea index [AHI] ≥5, median AHI 16.8, quartiles 1 to 3 8.9 to 32.6). Mean nadir oxygen saturations were 82% and 89% in patients with and without OSA, respectively. Ventricular premature complexes (≥5/hour) were more prevalent in subjects with OSA compared to subjects without OSA (median AHI 1.4, quartiles 1 to 3 0.5 to 3.0) during the night (12.2% vs 4.7%, p = 0.005) and day (14% vs 5.1%, p = 0.002). In multivariate analysis after adjusting for relevant confounders, AHI was independently associated with an increased prevalence of ventricular premature complexes at night (odds ratio per 1-U increase of log-transformed AHI 1.5, 95% confidence interval 1.1 to 2.0, p = 0.008) and during the day (odds ratio 1.37, 95% confidence interval 1.0 to 1.8, p = 0.035). In conclusion, the prevalence of ventricular premature complexes is increased in middle-aged patients with mainly mild or moderate OSA, suggesting an association between OSA and ventricular arrhythmias even in mild OSA.