An analytical method for the determination of along-fibre to cross-fibre elastic modulus ratio in ventricular myocardium--a feasibility study.

The myocardium of the left ventricle of the heart is a fibrous structure, the fibres being wound helically anticlockwise on the epicardium and changing progressively through the wall thickness to being wound helically clockwise on the endocardium. At any point, therefore, the material can be considered as transversely isotropic. For mechanically modelling the ventricle, two independent material properties, the along-fibre and across-fibre moduli of elasticity are required. This paper describes a computer method for determining these by using a finite element model and matching cavity volume and ventricle length against values derived from cineangiographic and pressure data. The method is applied to a group of patients with various cardiac diagnoses and the modular ratios for their myocardia are derived.