title: Determinants of biventricular cardiac function: a mathematical model study on geometry and myofiber orientation.
abstract: In patient-specific mathematical models of cardiac electromechanics, usually a patient-specific geometry and a generic myofiber orientation field are used as input, upon which myocardial tissue properties are tuned to clinical data. It remains unclear to what extent deviations in myofiber orientation and geometry between model and patient influence model predictions on cardiac function. Therefore, we evaluated the sensitivity of cardiac function for geometry and myofiber orientation in a biventricular (BiV) finite element model of cardiac mechanics. Starting out from a reference geometry in which myofiber orientation had no transmural component, two new geometries were defined with either a 27 % decrease in LV short- to long-axis ratio, or a 16 % decrease of RV length, but identical LV and RV cavity and wall volumes. These variations in geometry caused differences in both local myofiber and global pump work below 6 %. Variation of fiber orientation was induced through adaptive myofiber reorientation that caused an average change in fiber orientation of [Formula: see text] predominantly through the formation of a component in transmural direction. Reorientation caused a considerable increase in local myofiber work [Formula: see text] and in global pump work [Formula: see text] in all three geometries, while differences between geometries were below 5 %. The findings suggest that implementing a realistic myofiber orientation is at least as important as defining a patient-specific geometry. The model for remodeling of myofiber orientation seems a useful approach to estimate myofiber orientation in the absence of accurate patient-specific information.
authors: Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht, Maastricht University, Universiteitssingel 50, P.O. Box 616, 6200 MD, Maastricht, The Netherlands.|Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands.
authors: Marieke
authors: M
authors: Pluijmert
authors: Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht, Maastricht University, Universiteitssingel 50, P.O. Box 616, 6200 MD, Maastricht, The Netherlands.
authors: Tammo
authors: T
authors: Delhaas
authors: Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands.
authors: Adrián Flores
authors: AF
authors: de la Parra
authors: Institute of Computational Science, University of Lugano, Lugano, Switzerland.
authors: Wilco
authors: W
authors: Kroon
authors: Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Universiteitssingel 50, P.O. Box 616, 6200 MD, Maastricht, The Netherlands.
authors: Frits W
authors: FW
authors: Prinzen
authors: Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands. p.h.m.bovendeerd@tue.nl.
authors: Peter H M
authors: PH
authors: Bovendeerd
mesh_terms: D006321:Heart / Q000033:anatomy & histology* / Q000502:physiology*; D006801:Humans; D008962:Models, Theoretical; D009206:Myocardium / Q000166:cytology*; D016276:Ventricular Function / Q000502:physiology*
keywords: Adaptation; Biventricle; Computational physiology; Finite element