Respiratory effects of adaptive servoventilation therapy in patients with heart failure and Cheyne-Stokes respiration compared to healthy volunteers.

BACKGROUND Nocturnal adaptive servoventilation (ASV) therapy is now frequently used to treat Cheyne-Stokes respiration (CSR), which is highly prevalent in patients with moderate-to-severe heart failure (HF) and characterized by periodical breathing (hyperventilation). OBJECTIVES This study analyzed and compared the acute effects of a novel ASV device on carbon dioxide pressure (pCO2) and oxygen saturation (SaO2) in HF patients with CSR and healthy volunteers. The influence of being asleep or awake on the ASV algorithm was also determined. METHODS All subjects underwent ASV (PaceWave™, ResMed) for 1 h. Transcutaneous pCO2 (PtcCO2) and SaO2 were assessed transcutaneously, while wakefulness was analyzed using EEG recordings. Assessments were made 30 min before and after ASV, and during 1 h of ASV. RESULTS Twenty HF patients (19 male; age 79 ± 12 years) and 15 volunteers (13 male, age 25 ± 4 years) were included. When awake, ASV was associated with a trend towards a decrease in PtcCO2 and an increase in SaO2 versus baseline in HF patients (34.4 ± 3.2 to 33.7 ± 3.8 mm Hg and 93.8 ± 2.6 to 94.9 ± 2.6%, respectively) and volunteers (39.5 ± 3.0 to 38.2 ± 3.8 mm Hg and 96.9 ± 1.3 to 97.8 ± 0.9%). While asleep during ASV, PtcCO2 increased to 36.3 ± 3.8 mm Hg and SaO2 decreased to 93.8 ± 2.6% in HF patients, with similar changes in volunteers (PtcCO2 41.7 ± 3.0 mm Hg, SaO2 97.1 ± 1.2). All comparisons were statistically significant (p ≤ 0.05, except the PtcCO2 decrease in both groups when awake). CONCLUSIONS ASV therapy might result in hyperventilation when subjects are awake, but while asleep, PtcCO2 increased to mid-normal values, effects that would be favorable in HF patients with CSR.