title: Oxygen uptake efficiency slope, aerobic fitness, and V(E)-VCO2 slope in heart failure.
abstract: OBJECTIVE
  The oxygen uptake efficiency slope (OUES) is a promising submaximal index of exercise capacity, but its relationships to other indices characterizing physical fitness and ventilatory efficiency have not been widely investigated in heart failure.
  
  
  METHODS
  Sixty-three male patients with stable chronic heart failure performed a symptom-limited maximal exercise test on a cycle ergometer. Nineteen of them performed two exercise tests, 6 months apart. The peak oxygen uptake (VO2peak), ventilatory anaerobic threshold (VAT), OUES using all data (OUES(100)) or only the data up to the point where the RER was 1 (OUE(SRER1)), and V(E)-VCO2 slope were determined.
  
  
  RESULTS
  OUES(100), OUE(SRER1), and VAT were significantly correlated with measured VO2peak (r = 0.883, r = 0.814, and r = 0.877, respectively). The Bland-Altman limits of agreement between measured VO2peak and the values predicted by calculation from OUES(100), OUE(SRER1), and VAT were ±0.46, ±0.57, and ±0.48 L·min(-1), respectively. The variation in OUE(SRER1) between the first and second tests in the 19 patients was significantly related to the variation in VO2peak but not to the variation in the V(E)-VCO2 slope.
  
  
  CONCLUSIONS
  To predict VO2peak in patients with chronic heart failure, the index OUE(SRER1) is not better than the VAT. This, however, does not question the theoretical interest of its calculation because it may provide additional information on the oxygen uptake limitation steps.
authors.affiliation: Adaptation to Tropical Climate and Exercise Laboratory, EA 3596, University of French West Indies and Guiana, Guadeloupe, France. s_antoine@ymail.com
authors.forename: Sophie
authors.initials: S
authors.lastname: Antoine-Jonville
authors.forename: Aurélien
authors.initials: A
authors.lastname: Pichon
authors.forename: Ali
authors.initials: A
authors.lastname: Vazir
authors.forename: Michael I
authors.initials: MI
authors.lastname: Polkey
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Dayer
mesh_terms: D015308:Anaerobic Threshold; D000704:Analysis of Variance; D002245:Carbon Dioxide / Q000378:metabolism; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D006333:Heart Failure / Q000378:metabolism / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology*; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange
chemical_list: D002245:Carbon Dioxide