Cardiac Wall Mechanics and Torsion of the Left Ventricle during Ejection
Mathematical modeling is a common approach to study the mechanics of the wall of the left ventricle. In designing such a model generally symplifying assumptions are proposed on left ventricular geometry, myocardial tissue properties and stress or strain distribution across the wall. Common assumptions on geometry are a spherical (6, 8), a cylindrical (2) or ellipsoidal (7,10,12) shape of the left ventricle. Generally myocardial tissue is considered to be isotropic despite its obviously anisotropic properties. We developed a cylindrical, thick-walled model (1,2) which differs from other models by considering anisotropy of myocardial tissue and torsion of the left ventricle. Torsion reflects rotation of the apex with respect to the base around the long axis of the left ventricle, and is associated with shear deformation of the outer surface (epicardium) of the left ventricle when using a cylindrical coordinate system.
KeywordsLeft Ventricle Fiber Orientation Fiber Stress Myocardial Tissue Left Ventricular Geometry
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