Finite analytic model for left-ventricular systolic flow dynamics

In this paper, a model is described that provides a numerical simulation of flow in a contracting cavity with a single outlet and arbitrary user-supplied wall motion. The numerical solution is obtained by discretizing the Navier-Stokes equations for viscous fluid flow using the finite analytic (FA) method. This model is first compared with a closed-form potential flow solution using a spherical geometry. Then the model is applied to flow within the left ventricle of the human heart using successive cine-angiographic images of the left ventricular outline to obtain wall boundary conditions as input to the model. Qualitative differences existed between the potential and viscous flow solutions, dearly proving the importance of viscous effects and casting doubt on the use of potential flow models in the study of left ventricular fluid dynamics. Simulations of abnormal left ventricular wall movement displayed asymmetric flow, backflow, recirculation, and decreased pressure gradients compared with simulations of normal wall movement.