Modeling of concentric and eccentric hypertrophic growth in heart failure

Heart failure is a cardiovascular disease that causes changes in heart structure and function, reducing cardiac output. This disease can be categorized as either diastolic or systolic, and is a worldwide growing problem. In diastolic heart failure, the thickness of ventricular walls is increased and is associated with concentric hypertrophy. Systolic failure is characterized by dilation of the ventricles and is associated with eccentric hypertrophy. In this study, concentric and eccentric hypertrophies are deemed to be caused by pressure and volume overloads, respectively. The equations of concentric and eccentric hypertrophic growth have been implemented in COMSOL Multiphysics software using an idealized biventricular geometry and defining the microstructure with a rule-based approach. Simulation results of diastolic heart failure indicated that the ventricular wall thickness increased due to the excessive increase in pressure, with ventricular size remaining almost unchanged. Results for systolic heart failure indicated that the ventricular chamber volume increased dramatically, with wall thickness remaining relatively constant. The utilized approach for implementing growth equations can also be used in future for coupling with electromechanical models of the myocardium.