title: Oxygen uptake efficiency slope as a useful measure of cardiorespiratory functional reserve in adult cardiac patients.
abstract: In this study we aimed to elucidate the validity and usefulness of the oxygen uptake efficiency slope (OUES) in the evaluation of adult cardiac patients. Cardiopulmonary exercise tests were performed on a treadmill by 50 adult patients with chronic heart failure. The OUES was calculated from data for the first 75%, 90%, and 100% of exercise duration. The OUES is derived from the following equation: VO(2)=ax logV(E)+b, where VO(2) is oxygen uptake (ml/kg/min), V(E) is minute ventilation (l/kg/min), and the constant "a" represents OUES. We also determined the ventilatory anaerobic threshold (VAT). The correlation coefficient of the logarithmic curve-fitting model was [mean (SD)] 0.986 (0.009). The OUES could be used to discriminate effectively between New York Heart Association functional classes (P < 0.001). OUES and maximum VO(2) were significantly correlated (r=0.78, P < 0.01). Agreement between the OUES values for the first 90%, 75%, and 100% of the exercise was excellent (intraclass correlation coefficient = 0.99). Our results suggest that OUES is applicable to adult cardiac patients as an objective, effort-independent estimation of cardiorespiratory functional reserve.
authors.affiliation: Research Institute of Sports Medical Science Tokai University, 1117 Kitakaname, Hiratsuka, Kanagawa, 259-12, Japan. babar@keyaki.cc.u-tokai.ac.jp
authors.forename: R
authors.initials: R
authors.lastname: Baba
authors.forename: K
authors.initials: K
authors.lastname: Tsuyuki
authors.forename: Y
authors.initials: Y
authors.lastname: Kimura
authors.forename: K
authors.initials: K
authors.lastname: Ninomiya
authors.forename: M
authors.initials: M
authors.lastname: Aihara
authors.forename: K
authors.initials: K
authors.lastname: Ebine
authors.forename: N
authors.initials: N
authors.lastname: Tauchi
authors.forename: K
authors.initials: K
authors.lastname: Nishibata
authors.forename: M
authors.initials: M
authors.lastname: Nagashima
mesh_terms: D000368:Aged; D015308:Anaerobic Threshold; D005080:Exercise Test; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006331:Heart Diseases / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D012137:Respiratory System / Q000503:physiopathology*