Abstract

We introduce a CFD model for the numerical simulation of the heart hemodynamics in both physiological and pathological conditions, by accounting for all the physical processes that influence cardiac  flows: moving domain and interaction with electromechanics, transitional-turbulent  flows, cardiac valves and coupling with the external circulation. To impose a physiological displacement of the domain boundary, we employ a 3D ventricular electromechanical model coupled to a lumped-parameter (0D) closed-loop model of the circulation and the remaining cardiac chambers. To extend the ventricular motion to the endocardium of the remaining heart, we introduce a novel preprocessing procedure that combines an harmonic extension of the electromechanical displacement with the motion of the atria based on the 0D model. We thus obtain a one-way coupled electromechanics-fluid dynamics model in the ventricle(s). To better match the 3D CFD with blood circulation, we also couple the 3D CFD model to the 0D circulation model. We obtain a multiscale coupled 3D-0D fluid dynamics model that we solve via a segregated numerical scheme. We carry out numerical simulations for a healthy heart and we validate our model by showing that significant hemodynamic indicators are correctly reproduced.