Effect of treatment by nasal CPAP on cardiopulmonary exercise test in obstructive sleep apnea syndrome.
This study was done to evaluate whether cardiac dysfunction or abnormal measurements on cardiopulmonary exercise testing (CPET) can be improved after 2 months of nasal CPAP treatment. Twenty patients with moderate or severe OSAS received nasal CPAP treatment. All subjects also underwent blood pressure, simple spirometric, and arterial blood gas (ABG) measurements; cardiac evaluation by radionuclide scanning and CPET; and an overnight polysomnography sleep study before and after nasal CPAP treatment. No difference in left ventricular ejection fraction (LVEF) was found after 2 months of nasal CPAP treatment, but higher right ventricular ejection fraction (RVEF), VO2peak, VO2peak/kg and workpeak were observed. After 2 months of nasal CPAP treatment, these patients had a lower breathing reserve and a greater increase in anaerobic threshold and oxygen pulse. Moderate to severe OSAS patients before nasal CPAP treatment had abnormal CPET as reflected by lower RVEF, VO2peak/kg, workpeak, anaerobic threshold and oxygen pulse. These abnormalities can be improved after 2 months of nasal CPAP treatment.
Lin
Ching-Chi
CC
Chest Division, Department of Internal Medicine, Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan. cclin@ms2.mmh.org.tw
Lin
Ching-Kai
CK
Wu
Kun-Ming
KM
Chou
Chon-Shin
CS
D000328:Adult; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D017286:Polysomnography; D012129:Respiratory Function Tests; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology* / Q000628:therapy*; D016896:Treatment Outcome