Vortex dynamics in a model left ventricle during filling

Analysis of the properties of the left ventricle flow during filling (diastole) is known to allow early detection of potential malfunctions during the fundamental heart pumping phase (systole). Diagnoses are now usually based on Doppler measurement of the flow velocity for which interpretative schemes and quantitative references are sought. The flow inside an ideal model of the left ventricle is here studied numerically by a finite difference method in prolate spheroid moving coordinates. The axisymmetric assumption is employed in this first study. The vortex dynamics is characterised by the formation of a wake vortex attached at the valvular edge which is shed at the end of the ventricle expansion. Major features are its translation by self-induced velocity and vortex-induced separations from the ventricle internal wall. Results are represented as, and compared with, clinical data showing a good general agreement and allowing an improved physical interpretation of the latter. (C) 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved.