LAUSR

Abstract Funding Acknowledgements Type of funding sources: Private hospital(s). Main funding source(s): Learning Health Background and aim Electrocardiographic imaging (ECGI) is capable of performing an activation map with a single beat. The endo-epicardial system based on extracellular potentials allows for the reconstruction of endo-epicardial potentials both in the ventricles and the atria. The aim of this study was to compare the accuracy of the system to predict the site of origin (SOO) of ventricular focal arrhythmias (VAs) versus atrial focal arrhythmias (AAs). Methods We studied 55 consecutive patients referred for ablation of VAs or AAs that had an ECGI performed before ablation. Ablations were performed with remote magnetic navigation or manually. The localization of the VAs and AAs based on the ECGI and invasive electroanatomic mapping was performed using a segmental model of the atria and the ventricles. A perfect match (PM) was defined as a predicted location within the same anatomic segment, whereas a near match (NM) as a predicted location within the same segment or a contiguous one. The number of leads used for ECGI mapping, the agreement between the ECGI and the invasive map, and the success of the procedure were evaluated. Results Ablation was performed in 49 patients. We mapped 54 arrhythmias, 37 VAs (37 patients) and 17 AAs (12 patients). The results according to the atrial or ventricular origin of the arrhythmia are depicted in the table. Patients with AAs were older, no other differences were significant. The ECGI system correctly identified the SOO of both VAs and AAs in the same segment or a contiguous one in 100% of AAs and 97% of VAs, p=1.000. However, the percentage of a PM (Figure) was higher for AAs than for VAs (100% vs 76%, p=0.044). Conclusions The endo-epicardial ECGI correctly identified the origin of both ventricular and atrial arrhythmias. However, the accuracy was higher for the latter. PM in AA upper panel and VA lower panel