Omnipolar EGM Voltage Mapping for Atrial Fibrosis Identification Evaluated with an Electrophysiological Model

[EN] Atrial fibrillation (AF) is the most spread heart arrhythmia, whose mechanisms are not completely clear yet. Catheter ablation is a standard treatment, which isolates the area involved in the arrhythmia. Intracardiac electrograms (EGMs) are used to better understand the AF mechanisms and to find appropriate ablation sites. Bipolar EGMs (b-EGMs) are often employed, but their amplitude and shape depend on catheter orientation, limiting reliability. To avoid this uncertainty, an approach insensitive to catheter orientation, referred as Omnipolar EGM (OP-EGM) method, has been introduced, which uses an estimation of the electric field within a group of electrodes, referred as clique. In this work, we compare different mapping approaches based on b-EGMs and OPEGM signals in simulation including fibrosis, so to evaluate their ability to detect fibrosis and reproduce the spatial distribution of the voltage. Maps have been computed using two clique configurations (square and triangular), introducing or not a previous time alignment of the bEGMs. OP-EGM signals have been obtained by projecting the electric field along directions of its maximal excursion and its principal components. Results show that both cliques configurations present good performance, in terms of fibrosis detection and correlation with the reference voltage maps. In addition, the proposed alignment of b-EGMS improves maps based on OP-EGM signals, especially when square cliques are used.