Sleep Apnea, Mixed clinical trials

Effect of Servo-Ventilation on CO2 Regulation and Heart Rate Variability

Obstructive Sleep Apnea-Hypopnea Syndrome (OSAHS) is a condition where the upper airway partially collapses and closes. This can lead to sleep problems including low oxygen levels, poor sleep, elevated carbon dioxide levels in the blood, and activation of the sympathetic nervous system. Results from having disrupted sleep may be excessive daytime sleepiness along with behavioral, functional, cardiovascular and cognitive dysfunction. Continuous Positive Airway Pressure (CPAP) is the most effective treatment for OSAHS. CPAP stabilizes the airway and prevents instability and collapse. Other forms of positive airway pressure that are approved for the treatment of OSAHS include automatically adjusting CPAP, Bi-level Positive Airway Pressure (BiPAP), and automatically adjusting BiPAP. Automatically adjusting CPAP (Auto CPAP) evaluates the airflow pattern and adjusts pressure to optimize airflow. AutoSV (Auto Servo Ventilation) is a mode of positive airway pressure used to treat obstructive and complex central sleep apnea. In the prior study, the investigators found that the Auto S7 device led to more positive ventilation outcomes. Specifically, there was prolongation of QTc interval (the calculated time from the Q wave to the end of the T wave) and a tendency for greater premature ventricular contractions. The mechanistic basis for this could be attributable to excessive ventilation and related pro-arrhythmic effects of hypocapnia, though the investigators had not performed measures (partial pressure of CO2 (PaCO2) to detect this. In the current study, the investigators would like to investigate the hypothesis that the S7 device leads to lower PaCO2 levels than other devices, and whether these effects are augmented in individuals with complex sleep apnea in the setting of systolic heart failure.