Accurate localization of accessory pathways (APs) is essential for effective catheter ablation in Wolff–Parkinson–White syndrome, yet remains challenging in clinical practice, particularly in complex substrates or in the presence of multiple pathways. Current mapping strategies often rely on local activation timing or voltage-based descriptors, which do not fully capture the interplay between atrial and ventricular activations. This limitation may lead to incomplete identification and repeated interventions.
In this work, we propose two novel biomarkers derived from omnipolar electrograms (oEGMs) to improve AP localization by jointly characterizing temporal and propagation features of atrial and ventricular activity. The first marker, the temporal difference in local activation times (D-LAT), quantifies the temporal proximity between atrial and ventricular activations, highlighting regions of reduced activation delay. The second marker, the atrio-ventricular wavefront coherence (AVWC), measures the similarity between atrial and ventricular propagation patterns by combining directional alignment and signal amplitude into a normalized index ranging from 0 to 1.
The proposed framework was evaluated in two clinical cases exhibiting anterograde and retrograde conduction. In both cases, regions with low D-LAT and high AVWC showed strong spatial agreement with clinically identified ablation sites. D-LAT revealed areas of minimal temporal separation, consistent with direct electrical coupling, while AVWC identified regions where atrial and ventricular wavefronts propagate coherently, suggesting a shared conduction pathway. The spatial concordance between both markers provided a robust and complementary characterization of AP location.
These findings demonstrate that the joint analysis of temporal and propagation-based features derived from oEGMs enhances the identification of accessory pathways. The proposed biomarkers offer a physiologically meaningful description of atrio-ventricular interactions and have potential for integration into advanced high-density mapping systems, contributing to more precise and reliable ablation guidance.