Impact of Pulmonary Venous Locations on the Intra-Atrial Flow and the Mitral Valve Plane Velocity Profile

In this paper we present a three-dimensional computational fluid dynamics (CFD) framework of the left atrium (LA) and its pulmonary veins (PVs). The framework uses magnetic resonance imaging (MRI) to render the subject-specific atrial and venous geometries. The aim was first to investigate the diastolic flow field in an anatomically representative model of the LA and PVs. Second, to investigate the impact of different positions of the PVs on the intra-atrial flow and on the resulting velocity distribution at the mitral valve (MV) plane. Three 3D models with different venous entry locations were created for this purpose. In the model with anatomically based PV positions, the velocity profile at the MV plane showed qualitatively good agreement with the MRI flow measurements. When comparing the flow field in the three models, the results clearly illustrate that the PVs have a significant impact on the intra-atrial flow and the final velocity profile at the MV plane. Because the interpatient variability in PV number and branching patterns is large, the velocity profile at the MV plane should be considered as a subject-specific property. Therefore, we suggest that in order to obtain a physiological correct simulation of ventricular filling and MV opening dynamics, a subject-specific representation of the atrial and venous anatomies should be included in the simulation model.