REM sleep-related bradyarrhythmia syndrome.

Rapid eye movement sleep-related bradyarrhythmia syndrome is a rare condition marked by abnormal sinus arrest or atrioventricular conduction disturbance blocks during REM sleep unassociated with sleep disordered breathing. We present a case of a young man without a cardiovascular history exhibiting pauses of up to 9.7 seconds during polysomnography (PSG). Initially referred for suspected obstructive sleep apnea due to nocturnal awakenings with shortness of breath, confusion, and dizziness. PSG results were unremarkable apart from electrocardiogram findings revealing prolonged sinus pauses related to REM sleep. Evaluation via extended 14-day patch monitor revealed an overall normal sinus rhythm with the lowest heart rate recorded at 14 beats per minute and 412 pauses exceeding 2 seconds, with the longest pause lasting 12.5 seconds during nocturnal hours. A permanent pacemaker was considered, but after shared decision making with the patient, the decision was to continue monitoring without any intervention.