Abstract Body: Background:
Ventriculo-arterial (VA) coupling characterizes the interaction between the cardiac function and the arterial circulation afterload and reflects cardiovascular performance. We found, for the first time, that there is a significant VA decoupling with conventional CPR, which was ameliorated by automated head-up (AHUP)-CPR using active compression-decompression (ACD), impedance threshold device (ITD) as well as head and thorax elevation.
Research Questions:
How does the degree of active decompression (AD) influence VA coupling and its association with hemodynamic and perfusion outcomes during AHUP-CPR?
Methods:
Farm pigs (~40 kg) were intubated, ventilated, and monitored for hemodynamics, including end-tidal CO2 (ETCO2), and pressure-volume loops in right (RV | n=10) and left (LV | n =4) ventricles. After 10 minutes of untreated ventricular fibrillation, CPR started with 2 minutes each of C-CPR, ACD+ITD, and AHUP-CPR at 3 cm elevation. At minute 15, AD was paused, then resumed incrementally up to 4 cm. Statistical analysis was performed using a mixed-effects model to evaluate the effects of incremental AD on VA coupling, and a Spearman correlation to explore the relationship between VA coupling and hemodynamics.
Results:
Full AD (3cm or more) resulted in significantly enhanced VA coupling compared to no AD (p<0.05 in both ventricles) or minimal AD (1cm | p<0.05 RV and p=0.24 LV). Improved RV and LV VA coupling with full AD was associated with higher SV in both ventricles, as well as higher aortic pressures, and coronary and cerebral perfusions (table 1 and figure 1). Optimized VA coupling was also correlated with enhanced compression efficiency, which led to end compression volumes as a result of more efficient cardiac output.
Conclusion:
Full AD (3cm or more) when used with ITD during AHUP-CPR leads to optimal VA circulation. Optimized VA coupling in both ventricles resulted in enhanced cardiac filling and output, and subsequently, increased systemic, coronary and cerebral perfusion pressures. RV showed a different pattern to LV, likely due to its different load and contractile efficiency.