Abstract Mean circulatory filling pressure (MCFP) is a foundational hemodynamic concept, representing the average circulatory pressure in a no‐flow state and used to assess volume status and venous return. However, its measurement and clinical relevance remain debated. In this study, zero‐flow pressures were recorded in 14 healthy pigs following cardiac arrest. Measurements were taken for 10 min in the abdominal aorta and right atrium under two conditions: cardiac arrest induced by pentobarbital overdose or by ventricular fibrillation (VF), with half of the VF animals rendered hypovolemic. A validated computational model of cardiovascular physiology was used to simulate these scenarios. Pentobarbital caused a rapid pressure equilibration, with mean arterial pressure (MAP) falling from 47 ± 3.7 to 16 ± 2.5 mm Hg. In contrast, VF produced a dynamic pressure response: MAP dropped from 53 ± 4.7 to 17 ± 2.2 mm Hg while central venous pressure rose, producing a persistent retrograde pressure gradient (5 ± 2.1 mm Hg). In silico simulations closely matched these dynamics (normalized RMSE <5%) and confirmed the influence of reflex mechanisms. These results challenge the idea of MCFP as a stable, universal value. Zero‐flow pressures depend heavily on arrest method and reflexes, and computational modeling offers a valuable, ethical alternative to animal‐based investigations.
Loon et al. (Wed,) studied this question.