A geometric multiscale model for the numerical simulation of blood flow in the human left heart

TL;DR

This paper introduces a comprehensive multiscale computational model combining 3D fluid dynamics, electromechanics, and circulation models to simulate blood flow in the human left heart, validated by reproducing key hemodynamic indicators.

Contribution

It presents a novel coupled 3D-0D multiscale model integrating heart mechanics, valve dynamics, and circulation for realistic blood flow simulation.

Findings

Successfully simulates blood flow in the healthy left heart

Reproduces key hemodynamic indicators accurately

Validates the model against physiological data

Abstract

We present a new computational model for the numerical simulation of blood flow in the human left heart. To this aim, we use the Navier-Stokes equations in an Arbitrary Lagrangian Eulerian formulation to account for the endocardium motion and we model the cardiac valves by means of the Resistive Immersed Implicit Surface method. To impose a physiological displacement of the domain boundary, we use a 3D cardiac electromechanical model of the left ventricle coupled to a lumped-parameter (0D) closed-loop model of the remaining circulation. We thus obtain a one-way coupled electromechanics-fluid dynamics model in the left ventricle. To extend the left ventricle motion to the endocardium of the left atrium and to that of the ascending aorta, we introduce a preprocessing procedure according to which an harmonic extension of the left ventricle displacement is combined with the motion of the left atrium based on the 0D model. To better match the 3D cardiac fluid flow with the external blood circulation, we couple the 3D Navier-Stokes equations to the 0D circulation model, obtaining a multiscale coupled 3D-0D fluid dynamics model that we solve via a segregated numerical scheme. We carry out numerical simulations for a healthy left heart and we validate our model by showing that meaningful hemodynamic indicators are correctly reproduced.