Correlation between coronary perfusion pressure and quantitative ECG waveform measures during resuscitation of prolonged ventricular fibrillation

Abstract

Introduction: The ventricular fibrillation (VF) waveform is dynamic and predicts defibrillation success. Quantitative waveform measures (QWMs) quantify these changes. Coronary perfusion pressure (CPP), a surrogate for myocardial perfusion, also predicts defibrillation success. The relationship between QWM and CPP has been preliminarily explored. We sought to further delineate this relationship in our porcine model and to determine if it is different between animals with/without ROSC (return of spontaneous circulation).

Hypothesis: A relationship exists between QWM and CPP that is different between animals with/without ROSC.

Methods: Utilizing a prior experiment in our porcine model of prolonged out-of-hospital VF cardiac arrest, we calculated mean CPP, cumulative dose CPP, and percent recovery of three QWM during resuscitation before the first defibrillation: amplitude spectrum area (AMSA), median slope (MS), and logarithm of the absolute correlations (LAC). A random effects linear regression model with an interaction term CPP ROSC investigated the association between CPP and percent recovery QWM and how this relationship changes with/without ROSC.

Results: For 12 animals, CPP and QWM measures (except LAC) improved during resuscitation. A linear relationship existed between CPP and percent recovery AMSA (coefficient 0.27; 95%CI 0.23, 0.31; p<0.001) and percent recovery MS (coefficient 0.80; 95%CI 0.70, 0.90; p<0.001). A linear relationship existed between cumulative dose CPP and percent recovery AMSA (coefficient 2.29; 95%CI 2.0, 2.56; p<0.001) and percent recovery MS (coefficient 6.68; 95%CI 6.09, 7.26; p<0.001). Animals with ROSC had a significantly "steeper" dose-response relationship.

Conclusions: There is a linear relationship between QWM and CPP during chest compressions in our porcine cardiac arrest model that is different between animals with/without ROSC.

Figure 1

Calculation of the area under the curve coronary perfusion pressure. A: CPP is measured at the point just prior to compression upsurge in pressure (vertical black lines). B: AUC is calculated for the set of raw CPP values contained within each 30-second epoch and the cumulative AUC is calculated as a running total throughout the resuscitation. AoP: aortic pressure. RAP: right atrial pressure. CPP: coronary perfusion pressure. AUC: area under the curve.

Figure 2

Increase in CPP (A), cumulative dose CPP (B), and QWMs (C) over time during the 5 minutes of CPR prior to first rescue shock with associated lowess curve. CPP: coronary perfusion pressure. QWM: qualitative waveform measure. AMSA: amplitude spectrum area. MS: median slope. LAC: logarithm of absolute correlations.

Figure 3

Dose-response relationship between mean CPP (A) as well as cumulative dose CPP (B) and percent recovery of QWM (qualitative waveform measures) for the first 5 minutes of CPR before the first rescue shock. CPP: coronary perfusion pressure. AMSA: amplitude spectrum area. MS: median slope. LAC: logarithm of absolute correlations.

Figure 4

Relationship between QWM recovery and mean CPP (A, B, C) and cumulative dose CPP (D, E, F) in animals with and without ROSC. QWM: qualitative waveform measures. CPP: coronary perfusion pressure. ROSC: return of spontaneous circulation. AMSA: amplitude spectrum area. MS: median slope. LAC: logarithm of absolute correlations.