SlopeV˙o 2 v exercise intensity (ml/min2/kg) | Ventilatory anaerobic threshold (ml/min/kg) | Ventilatory anaerobic threshold (% normal) | SlopeV˙co 2 vV˙o 2 | SlopeV˙e v V˙co 2 | |
Normal controls (n=24) | 2.42 (0.68) | 29.0 (3.1) | – | 1.05 (0.13) | 30.3 (8.5) |
TF (n=30) | 1.68 (0.75)1-150 | 24.9 (3.6)1-150 | 85.1 (10.6)1-150 | 1.20 (0.18)1-150 | 41.5 (13.7)1-150 |
TGA (n=29) | 1.50 (0.64)1-150 | 22.6 (4.7)1-150 | 78.0 (13.3)1-150 | 1.26 (0.20)1-150 | 47.0 (15.4)1-150 |
Data are means (SD).
↵1-150 p < 0.005, normal controls v patients (TF and TGA).
Slope V˙co 2 vV˙o 2, slope of carbon dioxide outputv oxygen uptake from oxygen uptake at ventilatory anaerobic threshold until oxygen uptake at heart rate of 170 beats/min; slope V˙e vV˙co 2, slope of ventilationv carbon dioxide output during graded exercise; TF, tetralogy of Fallot after repair; TGA, transposition of the great arteries after atrial switch operation;V˙co 2, carbon dioxide output;V˙o 2, oxygen uptake. Ventilatory anaerobic threshold (% of normal) is expressed as a percentage of the mean value obtained in normal children and adolescents of same age and sex.