Left atrial intramyocardial fat at pulmonary vein reconnection sites during atrial fibrillation redo ablation

Figures

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  Figure 1. MDCT-derived 3D inFAT map. Septal view of a LA 3D inFAT map. Red areas correspond to dense inFAT (−194 to −50 HU), yellow-orange areas to fat-myocardial admixture (−50 to −5 HU), and blue areas do not harbour inFAT at all (>−5 HU). MDCT, multidetector computed tomography; inFAT, intramyocardial fat; LA, left atrial; HU, Hounsfield unit.

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  Figure 2. PVI line analysis. MDCT-derived 3D inFAT maps of the LA from different perspectives. A 6 mm wide band corresponding to PVI line trajectory was traced. Top-left panel: lateral–cranial view of the left PVI line; top-right panel: lateral–caudal view of the left PVI line; bottom-left panel: lateral–cranial view of the left PVI line; bottom-right panel: internal medial-to-lateral view of the left PVI line. MDCT, multidetector computed tomography; inFAT, intramyocardial fat; LA, left atrial; PVI, pulmonary vein isolation.

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  Figure 3. Procedural workflow. Pre-procedural MDCT scan of first AF ablations were post-processed. 3D inFAT maps were imported into the navigation system for PV-LA reconnection site analysis (identification of spatial colocalization between PV-LA reconnection points and inFAT). Also, PVI line was traced on 3D inFAT maps with the aim of quantifying the inFAT volume at each PVI line segment (total inFAT, dense inFAT, and fat-myocardial admixture). MDCT, multidetector computed tomography; AF, atrial fibrillation; LA, left atrium; inFAT, intramyocardial fat; PVI, pulmonary vein isolation.

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  Figure 4. Intramyocardial fat distribution at PVI line segments. First ablation MDCT-derived total inFAT volume distribution at various PVI line segments is depicted in a proportional manner (red ≥ 7.00 μL; orange ≥ 5.00 μL, yellow ≥ 3.00 μL, white < 3.00 μL). Both right PVs and left PVs show a higher amount of total inFAT at roof, antero-carinal, and antero-inferior segments. InFAT, intramyocardial fat; PVI, pulmonary vein isolation; MDCT, multidetector computed tomography; PV, pulmonary vein; AS, antero-superior segment; AC, antero-carinal segment; AI, antero-inferior segment; PI, postero-inferior segment; PC, postero-carinal segment; PS, postero-superior segment.

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  Figure 5. Total inFAT, dense inFAT, and fat-myocardial admixture volumes dot plots. Intramyocardial fat volumes comparison between reconnection segments and non-reconnection segments. Reconnection segments have significantly higher total inFAT, dense inFAT, and fat-myocardial admixture volumes compared to non-reconnection segments. InFAT, intramyocardial fat.