Staggered arrangement of high-density multielectrodes for improved omnipolar sensing in cardiac electrophysiology: an in silico study

Background and Objective: Accurate characterization of the cardiac substrate through multi-electrode catheters allows for the reconstruction of electroanatomical maps, guiding and optimizing ablation procedures. Omnipolar electrogram (oEGM) technology represents a significant advancement, allowing for orientation-independent tissue assessment. Given the advances in high-density catheter design offering alternative spatial electrode arrangements, the main aim of this study is to evaluate the performance of alternative clique geometries derived from a staggered grid of electrodes for oEGM estimation. Methods: Three clique configurations, including the regular triangular, rhomboid and hexagonal geometries were geometrically derived for staggered electrode grids for electric field estimation. Their performance was assessed using physiologically based in silico simulations, with controlled variations in anisotropy, tissue inhomogeneities, catheter orientation and interelectrode spacing. Reconstruction quality was quantified using the Residual-to-omnipolar ratio ( ROR ) and local activation time error ( ϵ LAT ), with a sensitivity analysis to different noise levels and angular characterization. Additionally, fibrotic tissue classification was evaluated using oEGM amplitudes through multiple lesion sizes. Results: The proposed methodologies generally improved oEGM reconstruction robustness compared with the conventional approaches although the cross configuration in rectangular grids remained competitive. Under healthy conditions, the hexagonal and rhomboid configurations generally provided the lowest ROR and ϵ LAT values, with reduced sensitivity to catheter orientation. In fibrotic tissue, the rhomboid clique showed the lowest reconstruction error. For fibrotic tissue classification, staggered configurations achieved higher sensitivity than rectangular grids through greater spatial sampling density, albeit at the expense of specificity. Conclusions: Three novel clique configurations for oEGM estimation in a staggered electrode array were proposed and evaluated. The results show improvements over standard rectangular grid approaches in both reconstruction quality and fibrotic tissue classification, highlighting the importance of balancing reconstruction performance, spatial coverage and electrode configuration. These results support the development of catheters with progressively reduced interelectrode spacing and optimized electrode geometries, subject to further clinical validation.