To validate the accuracy of a simplified bedside formula for estimating effective arterial elastance (Ea) in porcine models of ischemic cardiogenic shock (CS).
Approach:
Study Design: Twenty female Danish Landrace pigs were instrumented with a femoral arterial catheter, pulmonary artery catheter, and LV PV catheter. Ischemic CS was induced, and Ea was estimated from femoral arterial pressure and stroke volume, comparing it with PV-derived E…
Measurements: Ea was measured at healthy baseline, onset of CS, 60 minutes of untreated CS, and after dobutamine infusion. Correlations and agreement were evaluated using Pearson correlation and Bland–Altman analysis.
Key Findings:
Strong correlations between estimated and PV-derived Ea were observed at baseline, onset of CS, and established CS (r = 0.68–0.74, all P ≤ 0.002).
Correlation persisted during dobutamine infusion (r = 0.63, P = 0.020).
Bland–Altman analysis showed negligible bias at healthy baseline and CS onset, slight underestimation during established CS, and modest overestimation during dobutamine-treated CS.
Interpretation:
The estimated Ea reliably reproduced PV-derived Ea during various disease states.
Limitations:
The study was conducted in a porcine model, which may not fully replicate human physiology.
The sample size was limited to 20 pigs, which may affect the generalizability of the findings.
Conclusion:
The bedside estimation of Ea may provide a reliable method for monitoring afterload in ischemic cardiogenic shock.
