Recovery Kinetics of Oxygen Uptake in Patients with Various Degrees of Coronary Artery Disease

Journal of Clinical and Basic Cardiology 2007; 10 (1-4): 16-19

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Keywords: CPET,  Kardiologie,  Sauerstoff,  cardiology,  cardiopulmonary exercise test,  oxygen consumption

Background: Recovery indices of oxygen-consumption (VO2) kinetics have been observed as an important factor to evaluate and differentiate patients (pts) with various degrees of chronic heart failure (CHF) and less for pts with coronary artery disease (CAD). Objectives: To find the significance of recovery-VO2 kinetics indices in differentiating pts with various degrees of CAD as compared to normal individuals. Methods: 62 male pts were studied. They were divided into four groups according to their CAD degree: (A) 17 normal subjects (control); (B) 26 pts with onevessel disease (VD); (C) 11 pts with 2VD; (D) 8 pts with 3VD. All pts underwent a cardiopulmonary exercise test (CPET). The recovery indices measured were: (1) Half-time recovery (1/2tRec) of VO2; (2) 1/2tRec of oxygen pulse (O2P); (3) Total time recovery of VO2 (TtRec- VO2), until RER reached value of 1 or less. Results: 1/2tRec-VO2 differs significantly between groups A vs C and D (84 ± 20 vs 123 ± 36 and 134 ± 18); groups B vs D (100 ± 35 vs 134 ± 18) (p < 0.05). 1/2tRec-O2P differs significantly between groups A or B vs C or D (101 ± 30 or 123 ± 34 vs 162 ± 37 or 174 ± 40) (p < 0.05), while no significant differences are observed between groups A vs B and C vs D. The TtRec-VO2 index shows similar differences between the groups as the former one (7.6 ± 1.3 or 7.9 ± 1.4 vs 9.1 ± 1.9 or 9.2 ± 1.7, in respect to groups A, B, C and D; p < 0.05). Conclusions: Significant differences in the recovery indices of VO2 kinetics were observed among pts with various degrees of CAD. Such findings validate the recovery indices as important for better quantitative assessment of CAD pts.