Computer-aided detection of arrhythmogenic sites in post-ischemic ventricular tachycardia

Figures

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  Figure 1. Some examples of EGMs included in the dataset, with their spatial localization on the EA voltage map. Specifically, AVPs with deflections during and after the QRS (a,f), spreading after the end of the QRS depolarization (b,d), and completely falling within the surface QRS (h) are presented along with physiological potentials from scar (c), border zone (g), and healthy tissue (e,i). The EA voltage map was generated from CARTO 3 export files in MATLAB v2022a (MathWorks Inc., MA, USA).

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  Figure 2. Schematic representation of the 6-mm circular area CP determining the neighbors of the point P (in red) into the EA voltage map. As can be seen, the neighborhood is centered on the location of the EGM of interest (P) and spans for a radius equal to \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\epsilon$$\end{document}ϵ = 6 mm. Black dotted arrows represent the distances between each neighbor point and P. All EGM points falling within the selected area are exploited for the computation of the spatial features of P. The EA voltage map was created from CARTO 3 export files in MATLAB v2022a (MathWorks Inc., MA, USA).

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  Figure 3. Cumulative relevance score (percentage) for all the extracted features, from the most relevant to the less relevant one. Specifically: (1) MNP, (2) mean App in CP, (3) fragmentation, (4) standard deviation of the five highest CWT powers, (5) standard deviation of App in CP, (6) number of neighbors with App > 1.5 mV, (7) LAT, (8) relative PSD power in 180–200 Hz, (9) relative PSD power in 200–220 Hz, (10) relative PSD power in 100–120 Hz, (11) EGM App, (12) weighted mean App in CP, (13) sum of the five highest CWT powers, (14) relative PSD power in 140–160 Hz, (15) relative PSD power in 220–240 Hz, (16) relative PSD power in 80–100 Hz, (17) number of neighbors with App < 0.5 mV, (18) relative PSD power in 280–300 Hz, (19) relative PSD power in 40–60 Hz, (20) PKF, (21) relative PSD power in 160–180 Hz, (22) relative PSD power in 120–140 Hz, (23) CD, (24) relative PSD power in 260–280 Hz, (25) relative PSD power in 300–320 Hz, (26) relative PSD power in 240–260 Hz, (27) MNF, (28) number of neighbors with 0.5 mV < App < 1.5 mV, (29) PSR, (30) CV, (31) relative PSD power in 60–80 Hz, (32) relative PSD power in 0–20 Hz. Each bar represents the relevance score due to the features up to…

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  Figure 4. Some examples of voltage maps of procedures included in this work, in which AVPs correctly identified (green marbles), EGMs labelled as physiological but recognized as AVPs (purple marbles), EGMs annotated as AVPs but recognized as physiological (light blue marbles), and endocardial sites ablated during the procedure (red marbles) are depicted. On the left map (a), a channel entrance/exit to the slow conduction zone (black star) and a VT isthmus (black diamond) are depicted, while on the right map (b), a cluster of not-ablated AVPs located in apical LV area (black octagram) is highlighted. The EA voltage maps were generated from CARTO 3 export files in MATLAB v2022a (MathWorks Inc., MA, USA).