Assessing left atrial intramyocardial fat infiltration from computerized tomography angiography in patients with atrial fibrillation

Figure 1. Nineteen-segment semi-automatic LA region segmentation. PA, postero-anterior projection; LAO, left anterior oblique projection; LA, left atrial.

Figure 2. Violin plot reporting volumes and mean radiodensities of inFAT and its two subcomponents (dense inFAT and fat-myocardial admixture) in the study groups. P-values are referred to Kruskal–Wallis test. inFAT, infiltrated adipose tissue.

Figure 3. Antero-posterior (AP) and postero-anterior (PA) views of left intra-atrial fat maps in three patients from the different study groups (controls, paroxysmal AF, and persistent AF). Left atrial endocardial shell is depicted in light blue, while epicardial shell is shown in ‘glass-mode’. Dense fat and myocardial-fat admixture are reported in dark yellow and light yellow, respectively. AP, Antero-posterior; PA, postero-anterior; AF, atrial fibrillation.

Figure 4. Antero-posterior (AP) and postero-anterior (PA) views of LAWT maps in the same three patients of the previous figure, from the different study groups (controls, paroxysmal AF, and persistent AF). AP, Antero-posterior; PA, postero-anterior; AF, atrial fibrillation; LAWT, left atrial wall thickness.

Figure 5. Zoomed antero-posterior (AP) view of the inFAT map, superimposed on the LA wall thickness map, from a paroxysmal AF patient showing that LA inFAT distribution was distributed throughout the atrial wall, with no preference for epicardial or endocardial location. CTA-LA-WT, computerized tomography angiography-derived left atrial wall thickness. AP, Antero-posterior; PA, postero-anterior; AF, atrial fibrillation, inFAT, infiltrated adipose tissue; LA, left atrial.

Figure 6. Regional inFAT distribution analysis, stratified by the three study groups. Bar plot reports, for each of the evaluated segment, the mean regional inFAT distribution percentage. The asterisk denotes statistically significant differences across the three study group (one-way ANOVA test). inFAT, infiltrated adipose tissue.