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Thermodynamic bifurcation in anoxic heart: A far-from-equilibrium dissipative structure
Yves Lecarpentier1, Olivier Schussler2, Victor Claes3
1Centre de Recherche Clinique, Grand Hôpital de l'Est Francilien, Meaux, France.
Plos One
|March 7, 2024
Summary
Anoxia causes the mammalian heart to operate far from equilibrium, leading to a thermodynamic bifurcation and loss of stability around 60 minutes. This self-organization insight is crucial for heart transplant preservation.
Area of Science:
- Thermodynamics
- Cardiac Physiology
- Nonlinear Dynamics
Background:
- The isolated mammalian rat myocardium was studied under prolonged anoxia (3 hours).
- Anoxic hearts operate in a far-from-equilibrium state, showing non-linear relationships between thermodynamic force and flow.
Purpose of the Study:
- To investigate the thermodynamic consequences of anoxia on isolated mammalian rat myocardium.
- To understand the self-organization processes and dissipative structures in the cardiac system under stress.
Main Methods:
- Experimental investigation of isolated rat myocardium under a three-hour anoxic period.
- Analysis of thermodynamic force and flow non-linearity.
- Modeling using a one-dimensional nonlinear differential equation to identify thermodynamic bifurcation.
Main Results:
- The anoxic heart exhibited far-from-equilibrium behavior with non-linear thermodynamic force-flow relationships.
- A thermodynamic bifurcation occurred at approximately 60 minutes of anoxia, indicating a loss of thermodynamic stability.
- This bifurcation was linked to a change in the myosin molecular motor's force parameter, reflecting self-organization.
Conclusions:
- Anoxia induces self-organized processes and dissipative structures in the myocardium.
- The observed thermodynamic bifurcation highlights a critical instability point in the anoxic heart.
- Findings offer insights for myocardial protection strategies, particularly relevant for optimizing heart transplant viability.
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