Impact of Hypoglossal Nerve Stimulation on Nocturnal Asystole in a Patient with Severe Obstructive Sleep Apnea: A Case Report.

BACKGROUND Obstructive sleep apnea (OSA) is a highly prevalent condition associated with several cardiovascular diseases, and positive airway pressure (PAP) therapy is considered the standard treatment. In patients with OSA and nocturnal bradyarrhythmias, treatment with PAP therapy improves nocturnal bradyarrhythmias and is the basis for recommending OSA screening in patients with asymptomatic nocturnal bradyarrhythmia. As many patients do not tolerate PAP therapy, alternative treatment options like hypoglossal nerve stimulation (HNS) have been developed. Less is known regarding whether HNS therapy improves nocturnal bradyarrhythmia to a similar extent as PAP therapy. Our case highlights the unexpected return of nocturnal asystole in a patient who switched from PAP therapy to HNS therapy. CASE REPORT We report a case of a 77-year-old man with severe obstructive sleep apnea and nocturnal asystole treated with PAP therapy. Due to dissatisfaction with PAP therapy, he switched to HNS therapy. Upon discontinuing PAP therapy and during the self-titration phase of HNS therapy, the nocturnal asystole events returned unexpectedly despite symptomatic benefit from HNS therapy. Given the patient's concerns regarding the return of nocturnal asystole, he resumed PAP therapy and discontinued HNS therapy, which resolved the bradyarrhythmia. CONCLUSIONS The self-titration phase of HNS therapy can precipitate the return of comorbid conditions, like bradyarrhythmias, which can lead to patients abandoning therapy. Patients considering switching from PAP therapy to HNS therapy should be counseled that this can occur. Research evaluating the effects of HNS therapy on outcomes like nocturnal bradyarrhythmias using implanted loop recorders is warranted.