Impact of local left atrial wall thickness on the incidence of acute pulmonary vein reconnection after Ablation Index-guided atrial fibrillation ablation

Figures

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  Fig. 1. Example of wall thickness measurement. Panel A: Regions of interest were drawn inside the left atrium and ventricular apex. Panel B: Blood pool and myocardium intensity histograms were constructed from the regions of interest. The endocardial threshold value was calculated by averaging the means of the blood pool and myocardial image intensity. The epicardial threshold value was calculated as two standard deviations below the mean of the myocardial image intensity. Panel C: Locations for left atrial wall thickness measurement of the pulmonary vein (PV) antra were manually selected using a 3D segmentation of the left atrium. The yellow crosshair represents the location of wall thickness measurement on the anterior segment of the right inferior PV. Panel D: Multiplanar reformatted images were generated perpendicular to the atrial wall and the crosshair corresponds to the location chosen on the 3D segmentation (panel C). Subsequently, a line (in red) perpendicular to the atrial wall was drawn. Panel E: The intensity profile of the line perpendicular to the atrial wall was obtained. Atrial wall thickness was calculated using the patient-specific endocardial and epicardial thresholds.…

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  Fig. 2. Ablation procedure analysis. Panel A: Posteroanterior projection of a typical circumferential antral ablation approach. Ablation tags are automatically color coded based on Ablation Index (AI) values. Pink ablation tags represent AI values 380 to 499, whereas red tags represent AI values > 500. Panel B: Ablation tags were classified according to a 16-segment model for segmental analysis. Ablation tags belonging to additional ablation applications to treat acute pulmonary vein reconnection were excluded from analysis. Panel C: Minimum AI value, force–time integral (FTI), contact force (CF), ablation duration, power, impedance drop (impdrop) and maximum interlesion (IL) distance were determined for each segment. Ant = anterior, AU = arbitrary units, Inf = inferior, LCar = left carina, LIPV = left inferior pulmonary vein, LSPV = left superior pulmonary vein, Post = posterior, RCar = right carina, RIPV = right inferior pulmonary vein, RSPV = right superior pulmonary vein. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

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  Fig. 3. Acute reconnection and wall thickness per segment. Panel A: Sites of acute pulmonary vein reconnection were defined according to a 16-segment model. Numbers inside the stars indicate the total number of acute reconnections per segment. Panel B: Box plots showing local left atrial wall thickness per segment. Anterior/superior segments and posterior/inferior segments are displayed by red and pink colors, respectively. Ant = anterior, Inf = inferior, LCar = left carina, LIPV = left inferior pulmonary vein, LSPV = left superior pulmonary vein, Post = posterior, RCar = right carina, RIPV = right inferior pulmonary vein, RSPV = right superior pulmonary vein. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

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  Fig. 4. Comparison of reconnected and non-reconnected segments. Box plots showing difference in minimum Ablation Index value, force-time integral, contact force, ablation duration, power, impedance drop, maximum interlesion distance, and wall thickness between segments with acute reconnection (AR +) and segments without acute reconnection (AR −) for anterior/roof segments (panel A) and posterior/inferior segments (panel B). ns = not significant.