Table 3.
Right heart pressure and cardiac output in intact, spontaneously breathing rats exposed to normoxia (n = 5) or hypoxia n = 6)
| Heart Rate, beats/min | Stroke Volume, μl | Cardiac Output, ml/min | RV Systolic Pressure, mmHg | RV Diastolic Pressure, mmHg | Resistance, mmHg · ml−1 · min* | |
|---|---|---|---|---|---|---|
| Group 1: FiO2 =0.21 | ||||||
| Preinjection | 319 ± 123 | 90.8 ± 28.7 | 29 ± 9 | 19 ± 3 | 3 ± 5 | 0.7 ± 0.4 |
| Injection | 289 ± 16 | 126.9 ± 34.6 | 36 ± 8 | 29 ± 1† | 5 ± 4 | 0.8 ± 0.2 |
| Postinjection | 323 ± 30 | 98.9 ± 30.0 | 32 ± 10 | 22 ± 1 | 4 ± 5 | 0.8 ± 0.3 |
| Group 2: FiO2 = 0.12 | ||||||
| Preinjection | 283 ± 47 | 73 ± 18 | 21 ± 7 | 44 ± 11† | 3 ± 7 | 2.3 ± 0.9† |
| Injection | 268 ± 32 | 94 ± 30 | 25 ± 7 | 48 ± 11 | 6 ± 7 | 2.1 ± 0.9 |
| Postinjection | 265 ± 27 | 78 ± 29 | 21 ± 9 | 45 ± 14 | 6 ± 7 | 2.4 ± 1.1 |
Values are means ± SD.
*
Right ventricular systolic pressure is used as a surrogate for pulmonary artery systolic pressure. Thus total pulmonary vascular resistance is approximated as the quotient of the right ventricular systolic pressure and cardiac output.
†
P < 0.05 compared with preinjection in normoxia, adjusted for multiple comparisons.