Giving form to the function of the heart: embedding cellular models in an anatomical framework

A computational framework is presented for integrating the electrical, mechanical, and biochemical functions of the heart. The construction of efficient finite element representations of canine and porcine ventricular geometry and microstructure is outlined. Computational techniques are applied to solve large deformation soft tissue mechanics by using orthotropic constitutive laws for myocardial tissue and models of active tension generation embedded at the Gauss points in the finite element mesh. The reaction-diffusion equations governing electrical current flow in the heart are solved on a grid of deforming material points that access systems of ordinary differential equations representing the cellular processes underlying the cardiac action potential. Navier-Stokes equations are solved to predict coronary blood flow in a system of branching blood vessels embedded in the deforming myocardium.