TY - JOUR

T1 - The importance of the pericardium for cardiac biomechanics

T2 - From physiology to computational modeling

AU - Pfaller, Martin R.

AU - Hörmann, Julia M.

AU - Weigl, Martina

AU - Nagler, Andreas

AU - Chabiniok, Radomir

AU - Bertoglio, Cristóbal

AU - Wall, Wolfgang A.

PY - 2019/4

Y1 - 2019/4

N2 - The human heart is enclosed in the pericardial cavity. The pericardium consists of a layered thin sac and is separated from the myocardium by a thin film of fluid. It provides a fixture in space and frictionless sliding of the myocardium. The influence of the pericardium is essential for predictive mechanical simulations of the heart. However, there is no consensus on physiologically correct and computationally tractable pericardial boundary conditions. Here we propose to model the pericardial influence as a parallel spring and dashpot acting in normal direction to the epicardium. Using a four-chamber geometry, we compare a model with pericardial boundary conditions to a model with fixated apex. The influence of pericardial stiffness is demonstrated in a parametric study. Comparing simulation results to measurements from cine magnetic resonance imaging reveals that adding pericardial boundary conditions yields a better approximation with respect to atrioventricular plane displacement, atrial filling, and overall spatial approximation error. We demonstrate that this simple model of pericardial-myocardial interaction can correctly predict the pumping mechanisms of the heart as previously assessed in clinical studies. Utilizing a pericardial model can not only provide much more realistic cardiac mechanics simulations but also allows new insights into pericardial-myocardial interaction which cannot be assessed in clinical measurements yet.

AB - The human heart is enclosed in the pericardial cavity. The pericardium consists of a layered thin sac and is separated from the myocardium by a thin film of fluid. It provides a fixture in space and frictionless sliding of the myocardium. The influence of the pericardium is essential for predictive mechanical simulations of the heart. However, there is no consensus on physiologically correct and computationally tractable pericardial boundary conditions. Here we propose to model the pericardial influence as a parallel spring and dashpot acting in normal direction to the epicardium. Using a four-chamber geometry, we compare a model with pericardial boundary conditions to a model with fixated apex. The influence of pericardial stiffness is demonstrated in a parametric study. Comparing simulation results to measurements from cine magnetic resonance imaging reveals that adding pericardial boundary conditions yields a better approximation with respect to atrioventricular plane displacement, atrial filling, and overall spatial approximation error. We demonstrate that this simple model of pericardial-myocardial interaction can correctly predict the pumping mechanisms of the heart as previously assessed in clinical studies. Utilizing a pericardial model can not only provide much more realistic cardiac mechanics simulations but also allows new insights into pericardial-myocardial interaction which cannot be assessed in clinical measurements yet.

KW - Cardiac mechanical modeling

KW - Pericardium

KW - Boundary conditions

KW - Finite element simulation

KW - ATRIOVENTRICULAR PLANE DISPLACEMENT

KW - MECHANICAL-PROPERTIES

KW - VENTRICULAR MECHANICS

KW - PASSIVE MYOCARDIUM

KW - SOLE MECHANISM

KW - HEARTH

KW - ATRIAL

KW - PRESSURE

KW - QUANTIFICATION

KW - ORIENTATION

UR - https://arxiv.org/abs/1810.05451

U2 - 10.1007/s10237-018-1098-4

DO - 10.1007/s10237-018-1098-4

M3 - Article

VL - 18

SP - 503

EP - 529

JO - Biomechanics and Modeling in Mechanobiology

JF - Biomechanics and Modeling in Mechanobiology

SN - 1617-7959

IS - 2

ER -