New Adaptive Servo-Ventilation Device for Cheyne–Stokes Respiration

Abstract

Several studies have shown that patients with congestive heart failure (CHF) often suffer from the complication of sleep-disordered breathing (SDB), including Cheyne–Stokes respiration with central sleep apnea (CSR-CSA) as well as obstructive sleep apnea (OSA). These two types of SDB often coexist in such cases. CSR-CSA is characterized by cyclical recurrence of central apneas and hyperpneas with waxing and waning of the flow amplitude, which results from instability of the respiratory control system characterized by a tendency to hyperventilate due to the heart failure condition. Central apnea occurs when the Paco2 falls below the apnea threshold during sleep due to ventilatory overshoot. CSR-CSA is modifiable by several types of positive airway pressure (PAP) therapy; however, in the clinical setting, CSR-CSA patients with CHF tend to have poor adherence to the conventional PAP therapies, especially continuous PAP (CPAP), which are well established as treatments for OSA. Furthermore, they are well known to be “nonresponders” to conventional PAP as a therapy for CSR-CSA. In the CANPAP (Canadian Continuous Positive Airway Pressure for Patients with Central Sleep Apnea and Heart Failure Trial) study [1], CPAP only decreased the average apnea–hypopnea index (AHI) by about 50% (from 40 to 19/h). The post hoc analysis of the CANPAP. study [2] showed subjects with a residual CSR-CSA of AHI ≥ 15 using CPAP remained with a poor prognosis. These data suggest that other treatment options that can suppress the CSR-CSA more effectively (i.e., AHI < 15) and can produce better compliance are needed.