The values of the material constants used in the passive, active, and electrical constitutive laws discussed in the following sections were initially set to those in the cited references; however, several values were modified during the model validation process to obtain quantitatively realistic (i.e., physiologically observed) behavior.
You can replace the material behavior of any region of the model with any of
the Abaqus® built-in constitutive laws or with your own constitutive laws defined
using user subroutines. Details on both approaches can be found in the Abaqus Materials Guide. The material names for the electrical
analysis and mechanical analysis must use ABQ_CARDIAC_TISSUE and
ABQ_CARDIAC_TISSUE_HYBRID, respectively, as the leading
string.