Table 3.
Intra-class correlation coefficients (ICC), and Bland-Altman results between preload recruitable stroke work (PRSW(IVC)) obtained from inferior vena cava (IVC) occlusion and other single-beat surrogate metrics calculated from beat-by-beat baseline pressure-volume and arterial recordings in rats (n = 30).
| ICC | Bland-Altman, 95% LOA | |||||
|---|---|---|---|---|---|---|
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| ICC | Size | 95% CI | P | Lower | Upper | |
| PRSW(IVC) vs. single-beat surrogates of PRSW(IVC) | ||||||
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| ||||||
| PRSW(SB) | 0.631* | Moderate | −0.194–0.868 | < 0.001 | −20.027 | 90.911 |
| PWRmax-EDV | 0.637* | Moderate | 0.227–0.929 | 0.005 | −2.038 | 2.038 |
| PWRmax-EDV2 | 0.699* | Moderate | 0.359–0.857 | 0.001 | −1.903 | 1.903 |
| LVEFEA1 | 0.812* | Good | 0.603–0.911 | < 0.001 | −1.576 | 1.576 |
| LVEFEA2 | 0.799* | Good | 0.575–0.905 | < 0.001 | −1.621 | 1.621 |
|
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| PRSW(IVC) vs. other IVC occlusion-derived metrics | ||||||
|
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| dP/dtmax-EDV(IVC) | 0.653* | Moderate | 0.262–0.836 | 0.003 | −2.005 | 2.005 |
|
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| PRSW(IVC) vs. other single-beat surrogates of cardiac contractility | ||||||
|
| ||||||
| Ees(SB1) | 0.447 | - | −0.187–0.739 | 0.063 | −2.35 | 2.35 |
| Ees(SB2) | 0.436 | - | −0.210–0.734 | 0.069 | −2.364 | 2.364 |
| LVdP/dtmax-EDV | 0.611* | Moderate | 0.171–0.816 | 0.008 | −2.089 | 2.0891 |
| ARTdP/dtmax-EDV | 0.457* | Poor | −.165–0.744 | 0.057 | −2.336 | 2.336 |
| PmaxEDV | 0.656* | Moderate | −0.268–0.837 | 0.003 | −1.999 | 1.999 |
| LVESP-EDV | 0.694* | Moderate | 0.350–0.855 | 0.001 | −1.913 | 1.913 |
| ARTESP-EDV | 0.699* | Moderate | 0.353–0.856 | 0.001 | −1.91 | 1.91 |
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| PRSW(IVC) vs. load-dependent metrics | ||||||
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| LVdP/dtmax | 0.252 | - | −0.617–0.649 | 0.226 | −2.57 | 2.57 |
| ARTdP/dtmax | 0.155 | - | −0.835–0.604 | 0.332 | −2.656 | 2.656 |
| Pmax | 0.495* | Poor | −0.081–0.762 | 0.039 | −2.283 | 2.283 |
| LVESP | 0.465 | - | −0.246 −0.748 | 0.053 | −2.325 | 2.325 |
| ARTESP (0.9 × SBP) | 0.571* | Moderate | 0.083–0.797 | 0.015 | −2.162 | 2.162 |
| PWRmax | 0.335 | - | −0.433–0.687 | 0.146 | −2.485 | 2.485 |
| SW | −0.154 | - | −1.535–0.462 | 0.643 | −2865 | 2.865 |
PRSW(IVC), preload recruitable stork work obtained from IVC occlusion; PRSW(SB), stroke work (SW) and end-diastolic volume (EDV) ratio; PWRmax-EDV, power max (PWRmax) and EDV ratio; PWRmax-EDV2, PWRmax and squared of EDV ratio; LVEFEA1, afterload adjusted left ventricular ejection fraction using ventricular data; LVEFEA2, afterload adjusted left ventricular ejection fraction using arterial data; dP/dtmax-EDV(IVC), the relation between the maximal rate of rise of pressure and end-diastolic volume (EDV) obtained from IVC occlusion; Ees(SB1), left ventricular (LV) end-systolic pressure (LVESP) and end-systolic volume (ESV) ratio; Ees(SB2), arterial ESP (ARTESP, 0.9 × systolic blood pressure (SBP) and ESV ratio;; LVdP/dtmax-EDV, the maximal rate of rise of the left ventricular pressure (LVdP/dtmax) and EDV ratio; ARTdP/dtmax-EDV, the maximal rate of rise of the arterial pressure (ARTdP/dtmax) and EDV ratio; Pmax-EDV, maximal pressure (Pmax) and EDV ratio; LVESP-EDV, LVESP and EDV ratio, ARTESP-EDV, ARTESP and EDV ratio; LOA; limit of agreement.
significant observation.