Evaluation of Mechanical Unloading of a Patient-Specific Left Ventricle: A Numerical Comparison Study

In this study, we use a finite element model of left ventricular (LV) mechanics to evaluate the mechanical unloading of an end-diastolic (ED) geometry by using two different unloading algorithms: a direct method, and an iterative method. Furthermore, we evaluated the effects of using isotropic or anisotropic material properties. One representative ED geometry was derived from an atlas of LV geometries and used for mechanical unloading. We used a volume criterion instead of the more commonly used pressure criterion. The direct and iterative method gave identical results in unloaded geometries. Isotropic versus anisotropic material properties gave only minor differences in geometry. The main effect was found in unloading pressure. Overall, we conclude that both unloading algorithms can be used in further research. However, from a physiological and computational point of view, the direct method is preferable to the iterative method.