One hundred patients aged 21 years or older who have a hypoglossal nerve stimulation (HGNS) device implanted for obstructive sleep apnea, without a history of permanent AF, not on Class 1 or 3 antiarrhythmic medications and willing to participate in the study, will be randomized to "off-on" versus "on-off" periods (where "off" is turning off the HGNS device for one night and "on" is turning on the HGNS device), assuring no more than two consecutive days of either device use or not, over the ensuing 14 days. Participants will be fitted with an automatically recording electrocardiographic monitor. The primary endpoint will be the daily number of cardiac ectopic beats, and secondary endpoints: daily number of PACs, daily number of PVCs, and daily presence versus absence of AF episodes ≥ 30 seconds. Primary analyses will employ intention-to-treat principles, examining randomization assignment as the primary predictor.