Related Experiment Video
Updated: Jul 1, 2025

Designing a Bioreactor to Improve Data Acquisition and Model Throughput of Engineered Cardiac Tissues
Published on: June 2, 2023
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.
Abstract:
Thermodynamic consequences of a three-hour long anoxia were investigated on the isolated mammalian rat myocardium. The anoxic heart operated in a far-from-equilibrium manner as attested by the non-linearity between the thermodynamic force and the thermodynamic flow. When subjected to slight fluctuations due to anoxia, the open far-from-equilibrium cardiac system presented a thermodynamic bifurcation at ~ 60 minutes of anoxia. The bifurcation was characterized by a sudden change of direction in the bifurcation diagram of a one-dimensional nonlinear differential equation with one parameter and occurred at a non-hyperbolic fixed point at which moment the heart lost its thermodynamic stability. The parameter of the differential equation was the single force of the myosin molecular motor. These results helped to reflect a self-organized process and the occurrence of a dissipative structure. This offers valuable insights into our understanding of myocardial protection and could be of considerable interest, especially for heart transplants where the recipient must benefit from the donor's heart in the shortest possible time.
Related Concept Videos
The Nernst Equation
The interconnection between standard cell potentials and various thermodynamic parameters such as the standard free energy change ΔG° and equilibrium constant K has been previously explored. For example, a redox reaction involving zinc(II) and tin(II) ions at 1 M concentration with Eºcell = +0.291 V and ΔG° = −56.2 kJ is spontaneous.
Path Between Thermodynamics States
Thermodynamic Systems
Consider an example of tea boiling in a kettle. The...
Entropy Change in Reversible Processes
The statement can be further generalized to prove that entropy is a state function. Take a cyclic process between any two points on a p-V diagram.
Reversible and Irreversible Processes
Dynamic Equilibrium

