Differences in gas exchange of two representative PH patients (one shunt and one no shunt) and a normal subject.

<p>The responses of CPET in three female patients: one normal (aged 40 years; height, 160 cm; weight, 58 kg); one on-shunt-PH patient (aged 35 years; height, 157 cm; weight, 52 kg); and one shunt-patient (aged 38 years; height, 156 cm; weight, 54 kg). Symbols indicate 10-second averaged values. The course of CPET consisted of three minutes of rest, three minutes of unloaded cycling followed by increasing WR of 10 watts/min for PH patients and 20 watts/min for the control, and eventually four minutes of recovery. In the shunt-PH patient, PETO₂, </p><p></p><p></p><p>V<mo>˙</mo></p><p></p><p></p>E/<p></p><p></p><p>V<mo>˙</mo></p><p></p><p></p>O₂ (EqO₂), <p></p><p></p><p>V<mo>˙</mo></p><p></p><p></p>E/<p></p><p></p><p>V<mo>˙</mo></p><p></p><p></p>CO₂ (EqCO₂) and RER concurrently abruptly increased while PETCO₂ and SpO₂ abruptly decreased. The no-shunt-PH patient showed less changes in PETCO₂, PETO₂, RER, <p></p><p></p><p>V<mo>˙</mo></p><p></p><p></p>E/<p></p><p></p><p>V<mo>˙</mo></p><p></p><p></p>O₂ (EqO₂), <p></p><p></p><p>V<mo>˙</mo></p><p></p><p></p>E/<p></p><p></p><p>V<mo>˙</mo></p><p></p><p></p>CO₂ (EqCO₂) and SpO₂.<p></p

Correlation between Selected Resting Hemodynamics and Selected PFT Parameters for PH Patients.

<p>The abbreviation definitions are same as <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0121690#pone.0121690.t001" target="_blank">Table 1</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0121690#pone.0121690.t002" target="_blank">Table 2</a>.</p><p>Correlation between Selected Resting Hemodynamics and Selected PFT Parameters for PH Patients.</p

Changes in CPET Parameters from Rest to End of Unloaded Cycling in PH Patients and Control.

<p>Values are expressed as mean ± SD.</p><p>Δdenotes the changes from rest to the end of unloaded cycling exercise.</p><p>#p < 0.05, vs control group;</p><p>*p < 0.05, vs no-shunt PPH group using unpaired t test.</p><p>The abbreviation definitions are same as <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0121690#pone.0121690.t001" target="_blank">Table 1</a></p><p>Changes in CPET Parameters from Rest to End of Unloaded Cycling in PH Patients and Control.</p

Mean, SD, range and COV of OUE measurements during Cardiopulmonary Exercise Testing in IPAH patients (N = 32).

<p>***P<0.0001 by paired t test, versus OUES.</p><p>COV  =  coefficient of variation (SD/mean); all other abbreviation definitions are same as <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0098889#pone-0098889-t001" target="_blank">Table 1</a>.</p

Demographics, hemodynamics, Pulmonary Function Testing and Cardiopulmonary Exercise Testing parameters in IPAH patients and Control subjects.

<p>Values are expressed as mean ± SD and percentage of measured to predicted values (%pred).</p><p>*<i>p</i><0.05, †<i>p</i><0.005, ‡<i>p</i><0.0001, vs. controls using unpaired <i>t</i> test. NA = not applicable.</p><p>NYHA  =  New York Heart Association functional classification; mPAP  =  mean pulmonary artery pressure; mRAP = mean right atrial pressure; mPWP = mean pulmonary artery wedge pressure; TPVR  =  total pulmonary vascular resistance; FVC  =  forced vital capacity; FEV₁  =  forced expiratory volume in 1 second; MVV  =  maximum voluntary ventilation; DL_CO  =  gas transfer index or diffusing capacity for carbon monoxide; TLC  =  total lung capacity; AT  =  anaerobic threshold; %MVV  =  percentage of maximum voluntary ventilation; P_ETCO₂  =  partial pressure of end-tidal carbon dioxide; OUES  =  oxygen uptake efficiency slope; OUEP  =  oxygen uptake efficiency plateau; IPAH  =  idiopathic pulmonary arterial hypertension; %pred  =  percent of predicted; V˙O₂  =  peak oxygen uptake, STPD  =  standard temperature pressure dry; V˙E  =  minute ventilation, BTPS  =  body temperature pressure saturated; V˙CO₂  =  carbon dioxide output, STPD.</p

CPET of a PH patient who had a late-developing EIS at the end of exercise.

<p>The CPET course was comprised of three minutes of rest, three minutes of unloaded cycling followed by progressively increasing WR of 10 watts/min for the patient and eventually four minutes of recovery. Just before the end of exercise, the PH patient developed a late-developing EIS marked with the gas exchange findings of an abrupt increase in </p><p></p><p></p><p>V<mo>˙</mo></p><p></p><p></p>E/<p></p><p></p><p>V<mo>˙</mo></p><p></p><p></p>O₂ (EqO₂), <p></p><p></p><p>V<mo>˙</mo></p><p></p><p></p>E/<p></p><p></p><p>V<mo>˙</mo></p><p></p><p></p>CO₂ (EqCO₂), PETO₂ and RER, accompanying with a simultaneous decrease in PETCO₂ and SpO₂, then these changes suddenly returned toward their pre-shunt values when exercise stopped.<p></p

Correlation between Selected Resting Hemodynamics and Selected Exercise Parameters for PH Patients.

<p>*:<i>p</i><0.05;</p><p>**:<i>p</i><0.001</p><p>The abbreviation definitions are same as <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0121690#pone.0121690.t001" target="_blank">Table 1</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0121690#pone.0121690.t002" target="_blank">Table 2</a>.</p><p>Correlation between Selected Resting Hemodynamics and Selected Exercise Parameters for PH Patients.</p

Hemodynamics in Shunt-PH and No Shunt-PH Patients.

<p>Values are expressed as mean ± SD.</p><p>*<i>p</i> < 0.05, shunt group versus no-shunt group using unpaired <i>t</i> test.</p><p>NT-proBNP = n-terminal natriuretic peptide type-B; mPAP = mean pulmonary artery pressure; mRAP = mean right atrial pressure; PVR = pulmonary vascular resistance; CO = cardiac output; CI = cardiac index; PAWP = pulmonary arterial wedge pressure</p><p>Hemodynamics in Shunt-PH and No Shunt-PH Patients.</p

Demographics, 6MWD, Pulmonary Function Testing and Cardiopulmonary Exercise Testing Parameters in PH Patients and Control Subjects.

<p>Values are expressed as mean ± SD and percentage of measured to predicted values (%pred).</p><p>#p < 0.05, control group vs each group of PH patients;</p><p>*p < 0.05, shunt group versus no-shunt group using unpaired t test.</p><p>NYHA = New York Heart Association functional classification; FVC = forced vital capacity; FEV₁ = forced expiratory volume in 1 second; MVV = maximum voluntary ventilation; DL_CO = gas transfer index or diffusing capacity for carbon monoxide; AT = anaerobic threshold; OUES = oxygen uptake efficiency slope; peak </p><p></p><p></p><p>V<mo>˙</mo></p><p></p><p></p>O₂ = peak oxygen uptake, <p></p><p></p><p>V<mo>˙</mo></p><p></p><p></p>E = minute ventilation; <p></p><p></p><p>V<mo>˙</mo></p><p></p><p></p>CO₂ = carbon dioxide output,<p></p><p>Demographics, 6MWD, Pulmonary Function Testing and Cardiopulmonary Exercise Testing Parameters in PH Patients and Control Subjects.</p

Difference of CPET parameters between IPAH and control groups at different stages of exercise.

<p>The group mean±SD Values of IPAH) and control (NORMAL) groups are shown at stages of rest, unloaded cycling, AT, and peak exercise during incremental cycle ergometry tests. Values are. On the left side from top to bottom, they are OUE, V˙E/V˙CO₂ and P_ETCO₂.; on the right side from top to bottom they are V˙O₂, V˙CO₂ and V˙E. Statistically significant differences between groups at the same stage are shown as NS for no significance, * for P<0.05, ** for <i>P</i><0.005, below value symbol.</p