title: A New MRI-Based Model of Heart Function with Coupled Hemodynamics and Application to Normal and Diseased Canine Left Ventricles.
abstract: A methodology for the simulation of heart function that combines an MRI-based model of cardiac electromechanics (CE) with a Navier-Stokes-based hemodynamics model is presented. The CE model consists of two coupled components that simulate the electrical and the mechanical functions of the heart. Accurate representations of ventricular geometry and fiber orientations are constructed from the structural magnetic resonance and the diffusion tensor MR images, respectively. The deformation of the ventricle obtained from the electromechanical model serves as input to the hemodynamics model in this one-way coupled approach via imposed kinematic wall velocity boundary conditions and at the same time, governs the blood flow into and out of the ventricular volume. The time-dependent endocardial surfaces are registered using a diffeomorphic mapping algorithm, while the intraventricular blood flow patterns are simulated using a sharp-interface immersed boundary method-based flow solver. The utility of the combined heart-function model is demonstrated by comparing the hemodynamic characteristics of a normal canine heart beating in sinus rhythm against that of the dyssynchronously beating failing heart. We also discuss the potential of coupled CE and hemodynamics models for various clinical applications.
authors.affiliation: Department of Mechanical Engineering, Johns Hopkins University , Baltimore, MD , USA ; Institute for Computational Medicine, Johns Hopkins University , Baltimore, MD , USA.
authors.forename: Young Joon
authors.initials: YJ
authors.lastname: Choi
authors.affiliation: Institute for Computational Medicine, Johns Hopkins University , Baltimore, MD , USA ; Department of Biomedical Engineering, Johns Hopkins University , Baltimore, MD , USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Constantino
authors.affiliation: Department of Mechanical Engineering, Johns Hopkins University , Baltimore, MD , USA.
authors.forename: Vijay
authors.initials: V
authors.lastname: Vedula
authors.affiliation: Institute for Computational Medicine, Johns Hopkins University , Baltimore, MD , USA ; Department of Biomedical Engineering, Johns Hopkins University , Baltimore, MD , USA.
authors.forename: Natalia
authors.initials: N
authors.lastname: Trayanova
authors.affiliation: Department of Mechanical Engineering, Johns Hopkins University , Baltimore, MD , USA ; Institute for Computational Medicine, Johns Hopkins University , Baltimore, MD , USA.
authors.forename: Rajat
authors.initials: R
authors.lastname: Mittal
keywords: electromechanics; full heart function; heart failure; hemodynamics; immersed boundary method