Background: Sleep-disordered breathing (SDB) is a risk factor for bradyarrhythmia, which is reversible with positive airway pressure therapy.
Aims: The study aims to evaluate the occurrence and number of severe sinus bradycardia and advanced atrioventricular block (AVB) in patients with cardiovascular diseases and SDB risk factors.
Methods: The analysis covered 207 patients with cardiovascular diseases aged 59.4 (standard deviation [SD], 10.49) years, including 177 men (85.51%), hospitalized in the Department of Electro-cardiology and the Day Stay Cardiac Rehabilitation Ward Upper-Silesian Medical Centre in Katowice, Poland. The inclusion criterion was a high risk of SDB, in particular obstructive sleep apnea (OSA), in one of the following questionnaires: the Four-Variable Screening Tool, the STOP-Bang Questionnaire, and the Epworth Sleepiness Scale. Both level-3 portable sleep tests and electrocardiogram Holter recordings were made simultaneously.
Results: SDB was confirmed in 175 (84.5%) patients, including severe in 74 (35.7%), moderate in 42 (20.3%), and mild in 59 (28.5%) participants. The dominant type of SDB was OSA, which was found in 158 (76.3%) participants. The severe SDB was a predictor of third-degree AVB (odds ratio [OR], 11.61; 95% confidence interval [CI], 1.37-98.60), second-degree AVB type 2 (Mobitz) (OR, 4.51; 95% CI, 1.17-18.08), pauses above 3 seconds (OR, 10.26; 95% CI, 2.18-48.40), and sinus bradycardia below 40 bpm (OR, 3.00; 95% CI, 1.36-6.60) during sleep.
Conclusions: SDB, with particular emphasis on OSA, is a risk factor for sinus bradycardia and advanced AVB during sleep, which may lead to a hasty qualification for pacemaker implantation. The severity of SDB determines the frequency and number of bradyarrhythmic episodes.
Keywords: conduction disorders; pacemaker implantation; sleep-disordered breathing.