Table 2– Physiological and perceptual responses to cardiopulmonary exercise testing in pulmonary arterial hypertension (PAH) patients and in controls
Restiso-WR 1iso-WR 2Peak
PAHControlsPAHControlsPAHControlsPAHControls
WR W20±020±060±060±093±26*179±50
V′O2 L·min−1 (% pred)0.26±0.03 (14±5)0.24±0.03 (11±4)0.46±0.12 (23±9)0.66±0.12 (23±9)0.79±0.14 (40±13)0.86±0.17 (42±21)1.27±0.31* (62±17)*2.39±0.70 (106±13)
V′O2 per kg3.9±0.83.7±0.46.9±2.27.1±1.411.8±2.313.0±2.218.8±4.2*36.1±7.8
V′CO2 L·min−10.23±0.020.20±0.030.35±0.090.52±0.110.81±0.110.71±0.181.45±0.37*2.63±0.76
V′E L·min−111.4±2.2*9.7±0.918.9±3.1*14.6±1.636.7±7.5*23.1±5.167.7±19.1*108.1±9.9
V′E % MVC11±3*7±120±7*11±438±16*18±967±18*80±13
fR breaths·min−115±414±221±517±428±7*19±435±734±5
VT L0.80±0.190.71±0.120.95±0.220.87±0.171.36±0.291.21±0.211.94±0.473.28±0.62*
VT/IC %32±7*23±637±10*27±959±15*35±983±13*61±12
IC L2.6±0.7*3.2±0.52.7±0.7*3.3±0.52.5±0.7*3.5±0.52.4±0.8*3.6±0.5
IC/TLC %48±650±650±552±545±6*55±644±7*57±6
IRV L1.8±0.6*2.5±0.51.7±0.6*2.5±0.61.1±0.7*2.3±0.60.5±0.5*1.4±0.5
IRV/TLC %32±638±632±838±719±9*36±78±7*23±9
Dyspnoea Borg units0.0±0.00.0±0.00.5±0.3*0.1±0.33.4±1.7*0.6±0.66.8±1.8*4.1±1.5
Leg discomfort Borg units0.0±0.00.0±0.00.7±0.5*0.1±0.33.8±2.1*0.6±0.76.6±1.87.6±1.7
PET,CO2 mmHg28±4*42±329±5*43±328±6*45±326±6*40±3

  • 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 60 W; V′O2: oxygen uptake; % pred: % predicted; V′CO2: carbon dioxide production; V′E: minute ventilation; MVC: maximal ventilatory capacity; fR: respiratory frequency; VT: tidal volume; IC: inspiratory capacity; TLC: total lung capacity; IRV: inspiratory reserve volume; PET,CO2: end-tidal carbon dioxide tension. *: p<0.05, PAH versus controls at the same measurement point.