A generalized left ventricular dynamic compliance model: the chemo-mechanical capacitive transducer

The dynamic compliance model is generalized to study the chemical energy needed to change left-ventricular (LV) stiffness. The model has two capacitive ports, one using chemical power, and the other, hemodynamical power. Gibbs and Maxwell thermodynamic relations imply a reversible coupling between the two ports which creates a deactivation effect. A cross-bridges model, coupled to this LV model, has dissipative effects identical to those of the resistance of usual models. The new model presented is simple, but it suppresses two drawbacks of actual models: the non-energetic character of C(t) and a lack of interpretation in terms of muscle chemistry. It sets the stage for realistic models with three-state kinetics, excitation-contraction. ATP (adenasine triphosphate) hydrolysis and heat. Memory effects may be represented naturally by making the reaction orders functions of the integrated volume