In this study, we introduce a novel three-dimensional constitutive model that describes the electro-visco-elastic-growth response of the myocardium with a fully implicit staggered solution procedure for the strong electromechanical coupling.
This novel approach allows us to simulate and analyze the cardiac remodelling in actively contracting human ventricular heart models, which is characterized by a growing viscoelastic myocardium, where the growth direction is determined based on the mechanical state of each element at each time step.
A multiplicative decomposition method is adopted for the total deformation gradient into two main parts: a mechanical-active part and a growth part. The mechanical-active component is further divided into elastic, viscous, and active components.
To ensure unconditional stability during time integration, a backward Euler integration scheme is used.
Our developed model enables us to observe two types of growth within the myocardium: stretch-driven longitudinal (fibre) growth and stress-driven transverse (cross-fibre) growth. These capabilities provide valuable insights into how different mechanical impacts affect heart tissue development.
To validate the effectiveness of the developed approach, two distinct simulations related to pathological ventricular remodelling are conducted: one involving two divergent types of remodelling in a left ventricular model driven by hemodynamic overloads; another examining ventricular remodelling initiated by acute myocardial ischemia within a biventricular heart model, shown Figure 1.
These simulations not only demonstrate the new method's applicability but also highlight its potential for advancing our understanding of complex cardiac conditions and their impact on heart structure and function.