Comprehensive model for the simulation of left ventricle mechanics - Part 2 implementation and results analysis

The model of the left ventricle (LV) mechanics presented in Part 1 of the paper is used to simulate an entire cardiac cycle. Time-sequential canine heart data obtained by dynamic computerised tomography serve to initiate the simulation as well as to provide real data for evaluation of its results. The numerical predictions of the dynamic geometric changes are in good agreement with the tomographically determined changes that the ventricle undergoes throughout the cycle. Moreover, the simulation allows the evaluation of the time-varying stress and strain distributions in the ventricular wall and the active forces prevailing in the myocardial fibres. The simulated shape of the LV during the entire cardiac cycle reasonably compares with the experimental data. Furthermore, the twist angle of the ventricle as well as its maximal mean fibre strain are found to be in good agreement with physiological findings. Finally, a parametric study gives the relative influence of the anisotropy of the myocardium, its geometric and material nonlinearities and the mechanical activation on the mechanics of the left ventricle.