Sleep Apnea Syndrome and Nocturnal Bradyarrhythmias

Abstract

<h3>To the Editor.</h3> —The recent review of sick sinus syndrome by Belie and Talano^1,2in the March and April 1985 issues of theArchivesomitted an important point of differential diagnosis in this disorder. The authors stressed the importance of sinus bradycardia and sinus pauses during sleep as indications of sinus node disease, but did not mention sleep apnea syndrome (especially of the obstructive type) as an alternative, and relatively common, cause for this finding. The distinction is important, as pacemaker insertion is not required if adequate treatment of sleep apnea is achieved. Studies by Tilkian et al^3,4have provided the most data on arrhythmias and sleep apnea. In 25 patients with obstructive sleep apnea syndrome,4 they found no arrhythmias during wakefulness. During sleep, all but one exhibited marked sinus arrhythmia; nine had extreme sinus bradycardia (&lt;30 beats per minute); nine had asystoles; and four had second-degree atrioventricular block. Disappearance of these arrhythmias after