Table 6.
Hemodynamics and Gas Exchange Measurements in Controls and SIPE Subjects During Exercise, Unadjusted for Cardiac Output.
| P values
|
||||||
|---|---|---|---|---|---|---|
| Controls | SIPE-Susceptible Pre-Sildenafil | SIPE-Susceptible Post-Sildenafil | Pre-S vs. C | Post-S vs. C | Post-S vs. Pre-S | |
| External Work (W)† | 107.8±25.5 | 112.5±37.7 | 112.5±37.7 | 0.9 | 0.9 | 1.0 |
| V̇O2 (L.min−1 STPD) | 2.42±0.46 | 1.95±0.52 | 1.97±0.57 | 0.06 | 0.07 | 0.6 |
| V̇O2 (L.min−1 STPD.kg−1) | 29.1±4.6 | 25.6±5.7 | 25.9±6.2 | 0.2 | 0.3 | 0.5 |
| V̇E (L.min−1 BTPS) | 81.9±20.1 | 59.4±25.0 | 61.0±23.9 | 0.04 | 0.06 | 0.2 |
| Vt (L BTPS) | 2.85±0.50 | 2.12±0.63 | 2.20±0.51 | 0.0036* | 0.0103* | 0.3 |
| Vf (breaths.min−1) | 29.5±8.2 | 28.6±7.8 | 27.8±6.9 | 1.0 | 0.8 | 0.4 |
| HR (bpm) | 143.4±20.4 | 134.6±22.6 | 137.8±19.5 | 0.5 | 0.8 | 0.1 |
| CO (L.min−1) | 17.9±3.4 | 13.8±2.6 | 14.8±4.0 | 0.01* | 0.06 | 0.1 |
| Stroke volume (mL) | 126.4±26.4 | 105.7±31.2 | 109.2±34.9 | 0.2 | 0.3 | 0.3 |
| MAP (mmHg) | 126.2±12.0 | 129.6±14.7 | 128.1±13.3 | 0.8 | 0.9 | 0.7 |
| MPAP (mmHg) | 27.2±6.2 | 34.0±5.7 | 29.4±7.2 | 0.02 | 0.6 | 0.0208* |
| PAWP (mmHg) | 13.1±5.0 | 18.9±5.5 | 16.9±6.2 | 0.03 | 0.2 | 0.1 |
| CVP (mmHg) | 7.1±5.4 | 7.8±5.1 | 5.3±3.3 | 0.9 | 0.6 | 0.3 |
| SVR (dyn.s.cm−5) | 546±107 | 724±138 | 710±211 | 0.0106* | 0.02 | 0.6 |
| PVR (dyn.s.cm−5) | 62.6±15.1 | 84.2±22.4 | 69.3±24.8 | 0.03 | 0.7 | 0.0198* |
| CPA (mL.mmHg−1) | 4.00±0.82 | 3.38±0.75 | 3.74±0.94 | 0.2 | 0.7 | 0.1 |
| Ea (mmHg.mL−1) | 1.48±0.38 | 1.79±0.41 | 1.79±0.50 | 0.06 | 0.07 | 0.9 |
| PaO2 (mmHg) | 107.9±8.9 | 102.1±8.0 | 99.2±5.1 | 0.15 | 0.02 | 0.0337* |
| PaCO2 (mmHg) | 30.7±4.6 | 36.0±5.1 | 35.7±4.7 | 0.02 | 0.03 | 0.7 |
| Arterial pH | 7.31±0.05 | 7.35±0.03 | 7.36±0.03 | 0.07 | 0.0087* | 0.02* |
Results shown as mean±SD.
†
Not including resistive work due to motion of legs through the water, which adds approximately 50 W.
*
Statistically significant.
V̇O2, oxygen consumption; V̇E, respiratory minute volume; Vt, tidal volume; Vf, ventilatory frequency; HR, heart rate; CO, cardiac output; MAP, mean arterial pressure; CVP, central venous pressure; SVR, systemic vascular resistance; PVR, pulmonary vascular resistance; PaO2, PaCO2, arterial PO2 and PCO2, respectively (see Methods).