Table 2—

Cardiopulmonary exercise testing variables in pulmonary arterial hypertension (PAH) and chronic heart failure (CHF) patients

PAHCHFp-valueNormal limits
Peak WR W53±573±6<0.05129–241
 % pred36±442±3ns80–120
Peak V'O2 mL·kg−1·min−110.1±0.612.8±0.8<0.0123–32
 % pred40±344±3ns80–120
AT mL·kg−1·min−17.9±0.59.2±0.6ns12–17
 % pred57±458±3ns80–120
 % peak V'O274±371±3ns45–65
 % pred peak V'O231±232±2ns
Peak O2 pulse mL·beat−15.9±0.48.7±0.5<0.0019.1–16.5
 % pred53±464±4<0.0580–120
Peak RER1.15±0.021.19±0.02ns1.15–1.25
V'E L·min−1
Peak fc beats·min−1131±5115±50.06150–178
ΔV'O2/ΔWR above AT mL·min−1·W−15.3±2.38.4±3.8<0.029–11
fc recovery beats·min−111±210±2ns>12
  • WR: work-rate

  • V'O2: oxygen consumption

  • AT: anaerobic threshold

  • RER: respiratory exchange rate

  • V'E: ventilation

  • fc: cardiac frequency

  • V'CO2: carbon dioxide production

  • ΔV'O2/ΔWR: change in V'O2 per unit increase in WR

  • fc recovery: decrease in fc 1 min after peak exercise (lower limit of normal from 18)

  • % pred: per cent predicted

  • ns: nonsignificant