Adaptive Reorientation of Cardiac Myofibers: Comparison of Left Ventricular Shear in Model and Experiment

Mechanical load plays an important role in cardiac growth and remodeling. In a previous mathematical model study the hypothesis was tested that fiber cross-fiber shear acts as a stimulus for remodeling of the pattern of myofiber orientations [7]. It was found that reorientation in response to fiber cross-fiber shear yielded realistic longitudinal and transmural components of myofiber orientation. In this study, we investigated whether circumferential-radial shear, as determined experimentally with magnetic resonance tagging, can be reproduced in the model as well. Our results show that after myofiber reorientation differences in circumferential-radial shear between model and experiment were reduced significantly. However, a complete match could not be obtained through shear-induced myofiber reorientation alone.