Fluid-Structure-Electrophysiology interaction (FSEI) in the left-heart: a multi-way coupled computational model

In this study we present a computational model for unprecedented simulations of the left heart in realistic physiological conditions. To this aim, models for the electrical network of contractile muscular fibers (electrophysiology bidomain model), the myocardium mechanics (shells with hyperelastic and orthotropic constitutive relations) and the complex hemodynamics (direct numerical simulation of the Navier–Stokes equations) have been developed and multi-way coupled. The resulting multi-physics model, relying on the immersed-boundary method to cope with the complex fluid–structure interaction, is then validated by replicating the dynamics of the left heart considering simultaneously its atrium and ventricle, with the embedded aortic and mitral valves, and the thoracic aorta where blood is pumped. It is shown that the developed model, when given as input the parameters for the human heart, can reproduce the physiologic velocity and pressure signals obtained by cardiographic diagnostics of real patients.