Novel mapping techniques for rotor core detection using simulated intracardiac electrograms

Abstract

Background: Catheter ablation is associated with limited success rates in patients with persistent atrial fibrillation (AF). Currently, existing mapping systems fail to identify critical target sites for ablation. Recently, we proposed and validated several techniques (multiscale frequency [MSF], Shannon entropy [SE], kurtosis [Kt], and multiscale entropy [MSE]) to identify pivot point of rotors using ex-vivo optical mapping animal experiments. However, the performance of these techniques is unclear for the clinically recorded intracardiac electrograms (EGMs), due to the different nature of the signals.Objective: This study aims to evaluate the performance of MSF, MSE, SE, and Kt techniques to identify the pivot point of the rotor using unipolar and bipolar EGMs obtained from numerical simulations.Methods: Stationary and meandering rotors were simulated in a 2D human atria.The performances of new approaches were quantified by comparing the "true" core of the rotor with the core identified by the techniques. Also, the performances of all techniques were evaluated in the presence of noise, scar, and for the case of the multielectrode multispline and grid catheters.Results: Our results demonstrate that all the approaches are able to accurately identify the pivot point of both stationary and meandering rotors from both unipolar and bipolar EGMs. The presence of noise and scar tissue did not significantly affect the performance of the techniques. Finally, the core of the rotors was correctly identified for the case of multielectrode multispline and grid catheter simulations. Conclusion:The core of rotors can be successfully identified from EGMs using novel techniques; thus, providing motivation for future clinical implementations.

Computational Analysis of Mapping Catheter Geometry and Contact Quality Effects on Rotor Detection in Atrial Fibrillation

“…In the last decades, several works have analyzed atrial EGMs acquisition by different catheters using a simulation approach ( Alessandrini et al, 2017 ; Roney et al, 2017b ; Martinez-Mateu et al, 2018 , 2019 ; Hwang et al, 2019 ; Ravikumar et al, 2021 ), or have developed methods for rotor tracking with simulated and/or experimental EGMs ( Roney et al, 2014 ; Ugarte et al, 2015 ; Valinoti et al, 2015 , 2017 ; Ganesan et al, 2019a , b ).…”

“…A few recent studies ( Ganesan et al, 2020 ; Ravikumar et al, 2021 ) aimed at validating new algorithms for rotor detection, and simulated EGM acquisition using different mapping catheters.…”

“…Lately, Ravikumar et al (2021) tested the performance of several novel techniques developed to identify rotor pivot points in the case of multielectrode multispline (total of 160 signals) and grid catheter-based (total of 96 signals) sequential mapping for stationary rotors. Results in these two realistic clinical scenarios confirmed the capability of identifying the core of the stationary rotor with high sensitivities.…”

“…A few recent studies (Ganesan et al, 2020;Ravikumar et al, 2021) aimed at validating new algorithms for rotor detection, and simulated EGM acquisition using different mapping catheters. Ganesan et al (2020) have described a mapping algorithm that delineated the area of meandering repeating-pattern AF sources suggesting an optimal position for the subsequent catheter location.…”

Similarity Score for the Identification of Active Sites in Patients With Atrial Fibrillation

“…These techniques were shown to be accurate under some clinical limitations, such as reduced signal time duration and decreased spatial resolution. It was also demonstrated that the novel techniques could differentiate between the intracardiac electrograms (iEGMs) recorded from patients with successful and unsuccessful AF ablation ( Ravikumar et al, 2021 ). However, the use of individual approaches fails to robustly identify electrically active spatial sites for ablation ( Ravikumar et al, 2021 ), and therefore, efforts on developing combinatory approaches to identify the active AF sites are needed.…”