title: Effect of treatment by nasal CPAP on cardiopulmonary exercise test in obstructive sleep apnea syndrome.
abstract: 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.
authors.affiliation: Chest Division, Department of Internal Medicine, Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan. cclin@ms2.mmh.org.tw
authors.forename: Ching-Chi
authors.initials: CC
authors.lastname: Lin
authors.forename: Ching-Kai
authors.initials: CK
authors.lastname: Lin
authors.forename: Kun-Ming
authors.initials: KM
authors.lastname: Wu
authors.forename: Chon-Shin
authors.initials: CS
authors.lastname: Chou
mesh_terms: 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