Numerical analysis of hemodynamics in the left part of the heart, including simplified fluid-structure interaction methods

Abstract

The mitral valve is placed between the left atrium and ventricle. Both intra ventricular blood flow as well as valve dynamics are often subject to research. However, the inlet properties for such flows, which are created within the left atrium, are often replaced by simplified boundary conditions close to or on the mitral valve.

As the number of pulmonary veins as well as orifice size and location is known to vary between individuals, this report aims to study the effect of altered pulmonary vein locations on the trans-mitral and intra atrial blood flow.

This work is based on previous work and studies done by Sigrid Kaarstad Dahl and her colleagues, and the author himself. During previous studies, the pulmonary veins seemed to play an important role in the forming of the intra atrial vortices. Two dimensional simulations were extended to include variations of pulmonary vein size and location. Furthermore, a three dimensional model is created with the use of magnetic resonance imaging and three different pulmonary vein locations are tested.

The atrial systole is simulated with the Fluent software with mass flow boundary inlets at the pulmonary veins and a simplified ventricle represented by a long outlet funnel.

The simulations show clear differences in the formation of the intra atrial vortices, both in location and shape. Furthermore, trans-mitral flow pattern is showing to depend on the intra atrial vortices.