State of the art paper: Cardiac computed tomography of the left atrium in atrial fibrillation

Fig. 1. The current and potential value of computed tomography imaging in atrial fibrillation. (A) Contrast-enhanced computed tomography of the left atrium. (B) Semi-automatic segmentation of the left atrial wall and blood pool. (C) Identification of epicardial fat surrounding the left atrium where epicardial adipose tissue is defined as a hypodense layer with a density between −190 and −30 Hounsfield units. (D) Volumetric assessment of left atrium, peri-atrial fat and geographical distribution of peri-atrial fat and associated attenuation. CT, computed tomography; FAI, fat attenuation index; LA, left atrium; HU, Houndsfield units.

Fig. 2. Left atrial appendage morphology in patients from the SCOT-HEART study. A – “windsock”, B – “chicken wing”, C – “cactus”, D – “cauliflower”.

Fig. 3. Image demonstrating a left atrial appendage classification system based on the angle of the bend. The image on the left side shows a high risk left atrial appendage (LAA-H) with ≥90° angle bend (A) and the image on the right side shows a low risk left atrial appendage (LAA-L) with <90° angle bend (B).

Fig. 4. Atrial fibrillation simulation procedure - Integrating personalized left atrial anatomy to generate a left atrial wall thickness map for in silico atrial fibrillation simulations. CT, computed tomography; LA, left atrium.

Fig. 5. Computed tomography-based computational modelling evaluating the impact of changes in left atrial wall thickness on atrial fibrillation propagation. (A) Patient-specific computational model incorporating computed tomography-derived measurements of left atrial wall thickness. (B) Electrophysiology simulations showing patterns of wavefront propagation in computational models ""without wall thickness” and “with wall thickness” data. (C) and (D) Bar charts demonstrating the impact of left atrial wall thickness on the numbers of waves and phase singularities observed in atrial fibrillation simulations, with the atrial wall represented with 12 bins (0.5 ​mm width) or 3 bins (2 ​mm width).