TY - JOUR

T1 - Determinants of biventricular cardiac function: a mathematical model study on geometry and myofiber orientation

AU - Pluijmert, M.H.

AU - Delhaas, T.

AU - Flores De La Parra, A.

AU - Kroon, J.W.

AU - Prinzen, F.

AU - Bovendeerd, P.H.M.

PY - 2017/4/1

Y1 - 2017/4/1

N2 - 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 ∼8∘ predominantly through the formation of a component in transmural direction. Reorientation caused a considerable increase in local myofiber work (∼18%) and in global pump work (∼17%) 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.

AB - 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 ∼8∘ predominantly through the formation of a component in transmural direction. Reorientation caused a considerable increase in local myofiber work (∼18%) and in global pump work (∼17%) 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.

KW - Adaptation

KW - Computational physiology

KW - Finite element

KW - Biventricle

KW - Models, Theoretical

KW - Ventricular Function/physiology

KW - Humans

KW - Heart/anatomy & histology

KW - Myocardium/cytology

U2 - 10.1007/s10237-016-0825-y

DO - 10.1007/s10237-016-0825-y

M3 - Article

C2 - 27581324

SN - 1617-7959

VL - 16

SP - 721

EP - 729

JO - Biomechanics and Modeling in Mechanobiology

JF - Biomechanics and Modeling in Mechanobiology

IS - 2

ER -