Relation of daytime bradyarrhythmias with high risk features of sleep apnea

Bradyarrhythmias (BA) have been reported in patients with sleep apnea (SA), but the incidence of SA in patients with BA remains unclear. A case-control study was conducted to assess the prevalence of high-risk features of SA in patients with documented BA on 24-hour Holter monitoring compared with patients without BA. Controls were age-matched patients selected from those with no evidence of BA on 24-hour Holter monitoring. BA were defined as the presence of pauses of >3 seconds, regardless of the mechanism, and/or heart rate <40 beats/min during presumed waking hours (8 a.m. to 8 p.m.). High-risk features of SA were determined by the Berlin Questionnaire, with positive results defined as having '2 of 3 positive high-risk categories. Body mass index (BMI), hypertension, beta-blocker use, and other underlying characteristics were cataloged. Nineteen patients with documented BA and 47 with no BA were identified. The mean ages and BMIs in the active and control groups were not statistically significant. High-risk features for SA were present in 57.8% of patients in the BA group compared with 21.3% in the control group (p = 0.003). After controlling for age, BMI, hypertension, and beta-blocker use, patients with BA were 6 times more likely to have high-risk features of SA compared with those without BA (logistic regression odds ratio 6.1, 95% confidence interval 1.5 to 24, p = 0.012). In conclusion, irrespective of BMI, age, and other underlying risk factors, the presence of daytime BA was highly associated with high-risk features of SA.