Left-ventricular shape determines intramyocardial stroke work distribution

Abstract

The left-ventricle often undergoes large shape changes in the remodelling process, which is now considered to be an important indication of disease progression. Therefore, the influence on intramyocardial work load distribution was examined in a finite-element study. Hereto, models were constructed with varying shapes, ranging from an elongated ellipsoid to a sphere, while the initial cavity and wall volume was kept constant. A realistic transmural gradient in fiber orientation was considered. The passive myocardium was described by an incompressible hyperelastic material law with transverse isotropic symmetry. Activation was governed by the eikonal-diffusion equation. Contraction was incorporated using a mechanistic model. For each shape, a simulation was performed in which passive filling was followed by isovolumic contraction and ejection. It was found that the transmural distribution of the stroke work density was shape dependent, suggesting that the interaction between shape and intramyocardial mechanical heterogeneity could be important in the remodelling process. © 2011 Springer-Verlag Berlin Heidelberg.