Numerical studies of mitral valve regurgitation

Abstract

Mitral regurgitation (MR) has been studied through the use of computational fluid dynamics (CFD).The ambition of the work is to improve understanding of mitral regurgitation fluid dynamics in order to improve quantification techniques when diagnosing MR with Doppler echocardiography. The effect of relevant parameters on the blood net flow rate is established. Both k-epsilon and LES turbulence modeling has been used, in addition to the laminar model. Regions of the flow that maybe assumed to develop instantaneously are distinguished from slowly developing regions using transient simulation. The shape of the jet velocity profile as it enters the atrium has been examined for different grades of MR severity, and the cases have been compared using non-dimensional variables and scaling of parameters.

The results from the k-epsilon and LES viscosity models have been compared with experimentally obtained values from a similar problem, and both models were found to overestimate the jet spread rate slightly compared to the rate found in experiment.

Based on the findings of the CFD-modeling, the use of non-dimensionalized velocity profile plots is proposed as a possible technique when quantifying mitral regurgitation using Doppler echocardiography. These plots where found to scale very predictably with the size of the leakage orifice, which is a key parameter when quantifying mitral regurgitation.