Arrhythmias in sleep apnea.

A 23-year-old black female was referred to the University Hospital of Oklahoma because of "sleep trouble." She complained of falling asleep easily during the daytime. A sleep study was performed which showed prolonged apnea, up to 35 seconds, and prolonged asystole, up to seven seconds, with second-degree heart block. A tracheostomy was performed. She had lost some weight and did well until six months later, when she developed severe throbbing headache with visual blurring. She came to the emergency room and an ECG showed sinus bradycardia with prolonged sinus pauses, up to 2.6 seconds, and first- and second-degree AV block. She had no hypoxia and atropine was ineffective. Electrophysiologic studies were performed. Details of the case are described and mechanisms of the arrhythmias are discussed.