Evaluation and assessment of clique arrangements for the estimation of omnipolar electrograms in high density electrode arrays: an experimental animal model study

High-density catheters combined with Orientation Independent Sensing (OIS) methods have emerged as a groundbreaking technology for cardiac substrate characterisation. In this study, we aim to assess the arrangements and constraints to reliably estimate the so-called omnipolar electrogram (oEGM). Performance was evaluated using an experimental animal model. Thirty-eight recordings from nine retrospective experiments on isolated perfused rabbit hearts with an epicardial HD multielectrode were used. We estimated oEGMs according to the classic triangular clique (4 possible orientations) and a novel cross-orientation clique arrangement. Furthermore, we tested the effects of interelectrode spacing from 1 to 4 mm. Performance was evaluated by means of several parameters that measured amplitude rejection ratios, electric field loop area, activation pulse width and morphology distortion. Most reliable oEGM estimations were obtained with cross-configurations and interelectrode spacings = 2 mm. Estimations from triangular cliques resulted in wider electric field loops and unreliable detection of the direction of the propagation wavefront. Moreover, increasing interelectrode distance resulted in increased pulse width and morphology distortion. The results prove that current oEGM estimation techniques are insufficiently accurate. This study opens a new standpoint for the design of new-generation HD catheters and mapping software.

Automated summary

High-density catheters combined with Orientation Independent Sensing (OIS) methods have been shown to be groundbreaking for cardiac substrate characterisation. This study aimed to assess the reliability of estimating omnipolar electrograms (oEGMs) using different configurations and interelectrode spacings. The results demonstrated that the most reliable oEGM estimations were obtained with cross-configurations and 2 mm interelectrode spacings. Estimations from triangular cliques resulted in wider electric field loops and unreliable detection of the direction of the propagation wavefront. The findings highlight the need for improved oEGM estimation techniques and offer insights for the design of new-generation HD catheters and mapping software.