TABLE 2

Physiological and perceptual responses to cardiopulmonary exercise testing in pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) patients

Restiso-WR 1iso-WR 2Peak
PAHCTEPHPAHCTEPHPAHCTEPHPAHCTEPH
Work rate W20±020±040±040±0104±36*78±27
VO2L·min−10.33±0.110.34±0.060.58±0.130.63±0.150.78±0.150.79±0.141.34±0.37#1.07±0.39
VCO2 L·min−10.28±0.090.32±0.080.52±0.130.57±0.150.72±0.130.74±0.131.58±0.41*1.19±0.50
VE L·min−115.0±4.2*24.2±8.723.8±6.7*37.3±8.731.6±7.5*48.8±10.275.3±23.277.2±13.4
Respiratory rate breaths·min−119±4*22±524±731±1325±7*32±941±742±10
VT L0.81±0.20+1.14±0.611.03±0.29*1.32±0.421.33±0.35*1.59±0.341.85±0.431.91±0.59
IC L2.4±0.52.6±0.62.3±0.52.4±0.62.2±0.42.4±0.52.2±0.52.3±0.7
Dyspnoea Borg units0.4±0.70.3±0.70.9±1.1*2.9±2.01.9±1.6*4.2±2.56.7±1.57.4±1.7
PaO2 mmHg84.1±12.1*69.9±8.476.9±15.9*57.3±11.5
PaCO2 mmHg31.1±4.1#33.6±5.231.3±3.432.8±13.0
PA-aO2 mmHg25.9±11.5*46.0±10.045.8±16.9*62.2±10.6
VD/VT0.43±0.10*0.57±0.130.49±0.08*0.64±0.10

Data are presented as mean±sd. iso-WR 1: common standardised exercise work-rate (WR) of 20 W; iso-WR 2: common standardised exercise WR of 40 W; VO2: oxygen uptake; VCO2: carbon dioxide production; VE: minute ventilation; VT: tidal volume; IC: inspiratory capacity; PaO2: arterial partial pressure of oxygen; PaCO2: arterial partial pressure of carbon dioxide; PA-aO2: alveolar–arterial oxygen partial pressure difference; VD: dead space volume. *: p<0.05, PAH versus CTEPH at the same measurement point. #: p=0.06; : p=0.09; +: p=0.07.