Left Atrium Hemodynamic in Atrial Fibrillation and Normal Subjects

Atrial Fibrillation (AF) is associated with a five-fold increase in the risk of cerebrovascular events. Recent studies suggest that a computational fluid-dynamics (CFD) approach could provide insights on AF mechanisms thus potentially allowing a quantitative assessment of cardioembolic risk. The goal of this study was to use a previously developed patient specific CFD model of the left atrium (LA) to enhance differences in blood flow in AF patients and normal subjects. In this study we computed LA blood flow and derived parameters in normal subjects (NL), patients affected by paroxysmal AF (PAR-AF) and patients affected by persistent AF (PER-AF). Results showed mean peak velocities continuously decreasing from NL to PER-AF groups. In agreement, a lower number of vortex structures was observed in PER-AF with respect to PAR-AF and NL, thus limiting an effective washout of the LA and the left atrial appendage (LAA). Velocities at the LAA ostium and inside the LAA were also strongly reduced showing a limited washout effect as confirmed by blood stasis in terms of number of particles still present after five cardiac cycles (NL: 5±2, PAR-AF: 18±3, PER-AF: 41±10). The developed approach quantifies differences in LA hemodynamic between AF patients and NL.