PO-01-231 IDENTIFICATION OF ATRIAL ENDO-EPICARDIAL ASYNCHRONY USING SIGNAL FINGERPRINTING

Abstract

Atrial three-dimensional (3D) dissociation in conduction facilitates the development of atrial fibrillation (AF). Previous mapping studies revealed that patients with persistent AF have more endo-epicardial asynchrony (EEA) during SR than those without AF. Areas of EEA can be accurately identified by using unipolar electrograms (EGM). Alterations in endo-epicardial unipolar EGM features within EEA areas may provide novel insight into the electrical substrate of AF. To develop a novel method for estimating the degree of EEA by using unipolar EGM characteristics recorded from either the endo- and/or epicardium. During SR, intra-operative simultaneous endo-epicardial mapping (256 electrodes, 2 mm interelectrode distance) of the right atrium was performed in 86 patients. EEA was defined as an endo-epicardial dissociation exceeding 15 ms. EGM features, including voltages, low voltage areas (LVAs, <1.0 mV), potential types (single, short/long double and fractionated potentials) and fractionation duration (FD) were analyzed and correlated to EEA areas. The Asynchrony Fingerprinting Score (AFS) was developed based on uni- and multivariable logistic regression analyses. Three AFSs (Epi-AFS, Endo-AFS and EE-AFS) were established and assessed. EEA areas were characterized by a decrease in potential voltages, an increase in the number of long double potentials (LDPs) and fractionated potentials (FPs) and prolongation of double potentials (DPs) and FPs compared to non-EEA areas. Epi-AFS contained epicardial median voltage and the proportion of LDP, whereas the Endo-AFS contained the endocardial proportion of LVAs and single potentials (SPs). The EE-AFS, containing the proportion of endocardial LVAs, and the FD of epicardial DPs, showed the highest predictive value (AUC: 0.913) in determining the degree of EEA, although both Epi- and Endo-AFS also showed good predictive value with AUCs of 0.830 and 0.901 respectively. EEA is characterized by increased amounts of LVAs, LDPs and FPs, as well as an increase in the duration of both DPs and FPs. Epi-, Endo- and EE-AFS all showed good accuracy in identifying EEA areas. Therefore, AFS, as a novel approach utilizing integrated data from endo- or/and epicardium, may enable precise identification of EEA degree, including potentially arrhythmogenic substrates.