1003 Immediate Improvement of Second Degree Heart Block With Effective Treatment of Sleep-Disordered Breathing

Abstract

Abstract Introduction Cardiac arrhythmia and heart block in particular is commonly found in association with obstructive sleep apnea (OSA). Here we describe real-time responsivity of 2nd degree heart block to treatment of OSA with positive airway pressure (PAP) during a titration study. Report of case(s) Our patient is a 70-year old man without significant cardiovascular disease. He presented with loud snoring and excessive daytime sleepiness. A home sleep apnea test in July 2020 revealed obstructive sleep apnea (respiratory event index 20, oxygen saturation nadir 86%). The patient was treated with auto-adjusting continuous positive airway pressure (APAP) and had symptomatic benefit. His most recent machine data download suggested an elevated residual respiratory event index (REI) of 19.6, 16.5 of which were central. A split-night study was performed to re-characterize the nature of the patient’s obstructive sleep apnea and treatment needs. The baseline portion of the study (AHI 50.8, oxygen saturation nadir 86%) was notable for the presence of frequent 2nd degree heart block (171.0 events/hour of recording). During the titration portion of the study, frequent central sleep apneas emerged with the addition of PAP therapy, consistent with treatment-emergent central sleep apnea. The patient was transitioned to bilevel positive airway pressure spontaneous timed mode (BPAP ST), and a pressure setting of 13/6 cm of water with backup rate of 14 breaths per minute effectively controlled his sleep-disordered breathing. The heart block that had been observed during the baseline portion of the study dramatically improved with the start of BPAP ST. Once the patient’s sleep-disordered breathing was controlled, the patient’s heart block occurred at a rate of only 12.1 events/hour of recording. Conclusion Treatment of sleep apnea has been established to be beneficial for the improvement of cardiac arrhythmias. This case is remarkably instructive in that attainment of an effective treatment setting for sleep-disordered breathing resulted in an almost immediate improvement of heart block. Support (if any)