A multiscale CFD model of blood flow in the human left heart coupled with a lumped-parameter model of the cardiovascular system

Abstract

We present a novel computational model for the numerical simulation of the blood flow in the human heart by focusing on 3D fluid dynamics of the left heart. With this aim, we employ the Navier-Stokes equations in an Arbitrary Lagrangian Eulerian formulation to account for the endocardium motion, and we model both the mitral and the aortic 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 circulation and the remaining cardiac chambers, including the left atrium. To extend the left ventricle motion to the endocardium of the left atrium and the ascending aorta, we introduce a preprocessing procedure that combines an harmonic extension of the left ventricle displacement with the motion of the left atrium based on the 0D model. We thus obtain a one-way coupled electromechanics-fluid dynamics model in the left ventricle. To better match the 3D CFD with blood circulation, we also couple the 3D Navier-Stokes equations -with domain motion driven by electromechanics -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 left heart and we validate our model by showing that significant hemodynamic indicators are correctly reproduced. We finally show that our model is able to simulate the blood flow in the left heart in the scenario of mitral valve regurgitation.

life$^x$ - heart module: a high-performance simulator for the cardiac function. Package 1: Fiber generation

“…The initial development of life x has been oriented towards a heart module incorporating several state-of-the-art core models for the simulation of cardiac electrophysiology, mechanics, electromechanics, blood fluid dynamics and myocardial perfusion. Such models have been recently exploited for a variety of standalone or coupled simulations both under physiological and pathological conditions (see, e.g., [5,6,7,8,9,10,11,12,13,14]).…”

“…9 , ARPACK-NG10 , BLACS11 , Eigen 12 , FFTW 13 , GLPK 14 , HDF5 15 , HYPRE 16 , METIS 17 , MUMPS 18 , NetCDF 19 , OpenBLAS 20 , ParMETIS 21 , ScaLAPACK 22 , Scotch 23 , SuiteSparse 24 , SuperLU 25 , oneTBB 26 , p4est 27 .…”