TY - JOUR
T1 - Modelling Thermo-Electro-Mechanical Effects in Orthotropic Cardiac Tissue
AU - Ruiz-Baier , Ricardo
AU - Gizzi , Alessio
AU - Loppini , Alessandro
AU - Cherubini , Christian
AU - Filippi , Simonetta
JO - Communications in Computational Physics
VL - 1
SP - 87
EP - 115
PY - 2019
DA - 2019/10
SN - 27
DO - http://doi.org/10.4208/cicp.OA-2018-0253
UR - https://global-sci.org/intro/article_detail/cicp/13315.html
KW - Cardiac electromechanics, orthotropic active strain, thermo-electric coupling, scroll
wave propagation, numerical simulations.
AB - <p style="text-align: justify;">In this paper we introduce a new mathematical model for the active contraction of cardiac muscle, featuring different thermo-electric and nonlinear conductivity properties. The passive hyperelastic response of the tissue is described by an
orthotropic exponential model, whereas the ionic activity dictates active contraction incorporated through the concept of orthotropic active strain. We use a fully incompressible formulation, and the generated strain modifies directly the conductivity mechanisms in the medium through the pull-back transformation. We also investigate the
influence of thermo-electric effects in the onset of multiphysics emergent spatiotemporal dynamics, using nonlinear diffusion. It turns out that these ingredients have
a key role in reproducing pathological chaotic dynamics such as ventricular fibrillation during inflammatory events, for instance. The specific structure of the governing
equations suggests to cast the problem in mixed-primal form and we write it in terms
of Kirchhoff stress, displacements, solid pressure, dimensionless electric potential, activation generation, and ionic variables. We also advance a new mixed-primal finite
element method for its numerical approximation, and we use it to explore the properties of the model and to assess the importance of coupling terms, by means of a few
computational experiments in 3D.</p>