Joint Analysis of Morphological Parameters and In Silico Haemodynamics of the Left Atrial Appendage for Thrombogenic Risk Assessment

Figures

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  Figure 1. (a) Organization of the cohort of patients with atrial fibrillation (AF), transient ischemic attack (TIA), and cerebrovascular accident (CVA). (b) Computational pipeline followed in the study: data acquisition, left atrium (LA) segmentation from medical images, preprocessing, morphologic characterization of the LA and left atrial appendage (LAA), haemodynamic simulations, postprocessing, and statistical analysis of the data.

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  Figure 2. (a) Left atrial appendage division in three regions for the haemodynamic analysis (left) and morphological indices: ostium perimeter (postium) and area (Aostium), neck height (hLAA), distal point length (hθ), maximum ostium diameter (Dmax), origin of the LAA (OLAA), intersected point (pinter), anterior (dA) and posterior (dP) distance of the LAA and LAA, and centre of mass (pmass). (b) Examples of LAA with high and low tortuosity (left and right, respectively).

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  Figure 3. (a) Three-dimensional maps of endothelial cell activation potential (ECAP) for a transient ischemic attack or cerebrovascular accident patient (left) and a control case (right). High ECAP values (red areas) indicate a higher risk of thrombus formation due to low velocities and complex blood flow. (b) These velocities as well as the complexity of the flow within the LAA can be visualized with the streamlines for a thrombus case (left), while in a control case (right) flow remains in the ostium and does not reach the tip part of the LAA.

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  Figure 4. Model of the random forest performance in terms of Gini index. OSI: oscillatory shear index; RRT: relative residence time; LAAv: left atrial appendage volume; LAv: left atrium volume; TAWSS: time average wall shear stress; ECAP: endothelial cell activation potential.