title: Impact of continuous positive airway pressure treatment on right ventricle performance in patients with obstructive sleep apnoea, assessed by three-dimensional echocardiography.
abstract: BACKGROUND
  Obstructive sleep apnoea (OSA) is a predictor of right ventricle (RV) impairment. However, there is scant information on the effect of OSA treatment on RV performance. We sought to evaluate the impact of OSA treatment with a continuous positive airway pressure (CPAP) device on RV volume and function, as well as on variables related to pulmonary vascular haemodynamics.
  
  
  METHODS
  Fifty-six OSA patients and 50 controls were studied. All individuals underwent three-dimensional echocardiogram (3DE) to estimate RV volumes, function, pulmonary vascular resistance, and tricuspid regurgitation velocity. A total of 30 patients with apnoea-hypopnoea index greater than 20 were randomly selected to receive placebo (n=15) or effective CPAP (n=15) for 24 weeks. They underwent 3DE examination on three different occasions: at baseline, after 12 weeks, and after 24 weeks of CPAP or placebo.
  
  
  RESULTS
  Higher pulmonary vascular resistance (2.1 Wood's ± 0.5 vs. 1.8 Wood's ± 0.4), larger end-diastolic RV volume index (52.2 mL/m(2) ± 7.3 vs. 49.9 mL/m(2) ± 6.0), larger end-systolic RV volume index (18.7 mL/m(2) ± 4.3 vs. 15.4 mL/m(2) ± 3.6), and lower RV ejection fraction (64.3% ± 6.8 vs. 68.4% ± 5.9) were observed in the OSA group compared to non-OSA controls (P<0.05, all). In the effective CPAP group we observed the following changes from the baseline to the 24-week echo evaluation: (A) reduction in pulmonary vascular resistance (2.2 Wood's ± 0.3 to 1.8 Wood's ± 0.3); (B) reduction in the RV end-systolic volume index (20.3 mL/m(2) ± 4.5 to 16 mL/m(2) ± 2.1); and (C) increase in RV ejection fraction (63.0% ± 7.2 to 70.8% ± 0.9) (P<0.05 for all).
  
  
  CONCLUSIONS
  Twenty-four-week treatment with CPAP improved RV performance but did not change RV structural variables.
authors.affiliation: Department of Psychobiology, Federal University of Sao Paulo, Sao Paulo, Brazil. wercules.oliveira@yahoo.com.br
authors.forename: Wercules
authors.initials: W
authors.lastname: Oliveira
authors.forename: Dalva
authors.initials: D
authors.lastname: Poyares
authors.forename: Fatima
authors.initials: F
authors.lastname: Cintra
authors.forename: Marcelo L C
authors.initials: ML
authors.lastname: Vieira
authors.forename: Claudio H
authors.initials: CH
authors.lastname: Fischer
authors.forename: Valdir
authors.initials: V
authors.lastname: Moises
authors.forename: Sergio
authors.initials: S
authors.lastname: Tufik
authors.forename: Antonio
authors.initials: A
authors.lastname: Carvalho
authors.forename: Orlando
authors.initials: O
authors.lastname: Campos
mesh_terms: D016022:Case-Control Studies; D045422:Continuous Positive Airway Pressure; D019560:Echocardiography, Three-Dimensional; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D011652:Pulmonary Circulation / Q000502:physiology; D020181:Sleep Apnea, Obstructive / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D014655:Vascular Resistance / Q000502:physiology; D016278:Ventricular Function, Right / Q000502:physiology*