1208 A Case of Complex Sleep Apnea Improved with Cardiac Resynchronization Therapy

Abstract Introduction Congestive heart failure (CHF) is associated with higher risk of both obstructive (OSA) and central sleep apnea (CSA). While PAP therapy remains the gold standard in the treatment of obstructive sleep apnea, management of CSA needs to be tailored to the underlying pathophysiology. Optimal medical therapy for CHF is essential in the management of sleep-disordered breathing (SDB) among patients with CHF and reduced left ventricular ejection fraction (HFrEF). Cardiac resynchronization therapy (CRT) may have an important role. Report of case(s) We present the case of an 80 year old male, BMI 29 g/m2 who was evaluated at our sleep disorders center for the management of sleep apnea treated with CPAP 6 cm H2O and comorbid with HFrEF (ejection fraction 35% at the time of presentation) Therapy data from his CPAP device showed elevated residual AHI due to a combination of obstructive and central apneas as well as hypopneas. Significant leak and Cheyne-Stokes respiration were not detected. An empiric pressure increase was made as he was reluctant to return for PAP re-titration. He was also being treated with medical therapy for CHF and underwent CRT several months after presentation to the sleep clinic. Upon follow up he was found to have a dramatic improvement in residual events (AHI 31.2/hr- 6.7/hr) without further changes to CPAP. HFrEF increases risk of CSA through a vicious cycle stemming from significantly lower arousal threshold, high loop gain resulting in an exaggerated ventilatory response to arousals, and prolonged circulatory time leading to mismatched communication of arterial gas concentrations with the chemoreceptors. CHF may independently increase risk of OSA due to vascular engorgement of neck vessels that might affect upper airway patency especially among patients with hypervolemia. The terminal manifestation of a central apnea might be an occlusion of the pharyngeal airway requiring positive pressure to overcome the obstruction. This would explain why CPAP therapy might be effective among patients with HFrEF. Conclusion We conclude that the improvement in SDB in our patient is attributable to optimal medical therapy leading to euvolemia, CRT and medical therapy potentially improving cardiac systolic function and PAP therapy maintaining upper airway patency. Support (if any)