Rest | iso-WR 1 | iso-WR 2 | Peak | |||||
PAH | Controls | PAH | Controls | PAH | Controls | PAH | Controls | |
WR W | 20±0 | 20±0 | 60±0 | 60±0 | 93±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 kg | 3.9±0.8 | 3.7±0.4 | 6.9±2.2 | 7.1±1.4 | 11.8±2.3 | 13.0±2.2 | 18.8±4.2* | 36.1±7.8 |
V′CO2 L·min−1 | 0.23±0.02 | 0.20±0.03 | 0.35±0.09 | 0.52±0.11 | 0.81±0.11 | 0.71±0.18 | 1.45±0.37* | 2.63±0.76 |
V′E L·min−1 | 11.4±2.2* | 9.7±0.9 | 18.9±3.1* | 14.6±1.6 | 36.7±7.5* | 23.1±5.1 | 67.7±19.1* | 108.1±9.9 |
V′E % MVC | 11±3* | 7±1 | 20±7* | 11±4 | 38±16* | 18±9 | 67±18* | 80±13 |
fR breaths·min−1 | 15±4 | 14±2 | 21±5 | 17±4 | 28±7* | 19±4 | 35±7 | 34±5 |
VT L | 0.80±0.19 | 0.71±0.12 | 0.95±0.22 | 0.87±0.17 | 1.36±0.29 | 1.21±0.21 | 1.94±0.47 | 3.28±0.62* |
VT/IC % | 32±7* | 23±6 | 37±10* | 27±9 | 59±15* | 35±9 | 83±13* | 61±12 |
IC L | 2.6±0.7* | 3.2±0.5 | 2.7±0.7* | 3.3±0.5 | 2.5±0.7* | 3.5±0.5 | 2.4±0.8* | 3.6±0.5 |
IC/TLC % | 48±6 | 50±6 | 50±5 | 52±5 | 45±6* | 55±6 | 44±7* | 57±6 |
IRV L | 1.8±0.6* | 2.5±0.5 | 1.7±0.6* | 2.5±0.6 | 1.1±0.7* | 2.3±0.6 | 0.5±0.5* | 1.4±0.5 |
IRV/TLC % | 32±6 | 38±6 | 32±8 | 38±7 | 19±9* | 36±7 | 8±7* | 23±9 |
Dyspnoea Borg units | 0.0±0.0 | 0.0±0.0 | 0.5±0.3* | 0.1±0.3 | 3.4±1.7* | 0.6±0.6 | 6.8±1.8* | 4.1±1.5 |
Leg discomfort Borg units | 0.0±0.0 | 0.0±0.0 | 0.7±0.5* | 0.1±0.3 | 3.8±2.1* | 0.6±0.7 | 6.6±1.8 | 7.6±1.7 |
PET,CO2 mmHg | 28±4* | 42±3 | 29±5* | 43±3 | 28±6* | 45±3 | 26±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.