A Poroelastic Computational Modeling Framework Coupling Left Ventricular Cardiac Mechanics and Myocardial Perfusion.

We present a computational modeling framework coupling a poroelastic left ventricle (LV) with lumped-parameter descriptions of the coronary and systemic circulations in a closed-loop system. The finite element method, with P1-P1-P0 discretization of the displacement, Darcy flow and pore-pressure fields, is used to solve the boundary value problem associated with the poroelastic formulation. We show that simulation of the isolated non-contractile poroelastic LV can reproduce perfusion-induced stiffening features found in measurements of pressure-volume relationships with less than 1 mmHg error. Simulations coupling the poroelastic LV with systemic and coronary circulatory models also show that the framework can produce phasic changes in coronary flow rate and myocardial wall volume that agree with the experiments. Using the framework, we investigate the effects of coronary sinus (CS) resistance on myocardial perfusion. We show that increasing CS resistance attenuates coronary flow rate, increases myocardial pore pressure, and promotes myocardial swelling.