Table 2.
Left ventricular pressure-volume variables.
| Variable | Slope | 95% CI | p-value vs. 1 | r2 | Y intercept | 95% CI | p-value vs. 0 |
|---|---|---|---|---|---|---|---|
| LV ESP | 1.02 | 0.95–1.08 | 0.626 | 0.94 | ÷3.82 | ÷9.86–2.22 | 0.211 |
| LV EDP | 0.87 | 0.78–0.96 | 0.005 | 0.85 | 0.02 | ÷0.81–0.86 | 0.957 |
| LV ESV | 1.02 | 0.94–1.10 | 0.694 | 0.90 | 0.70 | ÷4.55–5.94 | 0.792 |
| LV EDV | 1.01 | 0.95–1.06 | 0.744 | 0.95 | ÷1.77 | ÷11.58–8.04 | 0.720 |
| LV SW | 1.05 | 0.97–1.12 | 0.254 | 0.91 | ÷463.6 | ÷1115.0–188.1 | 0.160 |
| LV SV | 1.04 | 0.94–1.14 | 0.444 | 0.86 | 2.80 | ÷12.22–6.61 | 0.554 |
| LV EF | 0.94 | 0.84–1.03 | 0.172 | 0.85 | 3.42 | ÷2.09–8.93 | 0.220 |
| LV Ea | 1.01 | 0.93–1.10 | 0.777 | 0.89 | ÷0.04 | ÷0.13–0.05 | 0.321 |
| LV dP/dt (max) | 0.96 | 0.92–0.99 | 0.016 | 0.98 | 9.59 | ÷49.97–69.15 | 0.749 |
| LV dP/dt (min) | 0.92 | 0.86–0.99 | 0.026 | 0.91 | ÷139.5 | ÷276.2; ÷2.9 | 0.045 |
| LV tau | 1.01 | 0.90–1.12 | 0.899 | 0.82 | ÷3.52 | ÷7.79–0.75 | 0.104 |
Slopes and intercepts with 95 % confidence intervals (95%CI) from linear fits of each variable during mechanical ventilation versus apnea. n=72 for all. LV, left ventricular; ESP, end-systolic pressure; EDP, end-diastolic pressure; ESV, end-systolic volume; EDV, end-diastolic volume; SW, stroke work; SV, stroke volume; EF, ejection fraction; Ea, arterial elastance; dP/dt, first derivative of pressure.