title: Body forces and pressures in elastic models of the myocardium.
abstract: Tension strands are introduced to represent active myocardial fibers. They create one body force proportional to the divergence of the tension-direction vector, and a second equal to the tension divided by the radius of curvature. Explicit solutions to isotropic linearly elastic tensor equations with these body forces are found for the radially-symmetric, linearly-isotropic, elastic spherical heart with arbitrary radial body force. They confirm experiments showing supraluminal intramural pressures. Such pressures may affect coronary perfusion. A tension strand model which is a reasonable compromise between actual myofibrillar geometry and analytical simplicity is the iso-oblique, terminating, nonintersecting model. The body force from that or any other axially symmetric body force can be the forcing term for equations in which the heart is modeled as a thin, ellipsoidal, elastic membrane.
mesh_terms: D002302:Cardiac Output; D006321:Heart / Q000502:physiology*; D008433:Mathematics; D008955:Models, Cardiovascular; D009200:Myocardial Contraction; D011312:Pressure; D013599:Systole