A novel catheter-guidance algorithm for localization of atrial fibrillation rotor and focal sources

Abstract

Locating atrial fibrillation (AF) focal and rotor sources can help improve target ablation therapy for AF. However, it remains unclear how to use the information provided by multi-polar diagnostic catheters (MPDC) to locate AF sources. Our aim was to develop a catheter-guidance algorithm to locate AF focal and rotor sources using a conventional MPDC. We simulated a 10 cm x 10 cm atrial tissue with focal and rotor sources using the Nygren et al. ionic model. We modeled a Lasso MPDC with 20-unipole electrodes placed with a spacing of 4.5-1-4.5 mm (diameter, d=15 mm) along a circle to obtain 10-bipole electrograms. Staring from an initial location, the algorithm, which was blinded to the location and type of the AF source, iteratively advanced the MPDC by moving its center to the location of the first activated bipole (FAB). The algorithm located an AF source if a stopping condition for either source was satisfied using bipole electrogram characteristics extracted from the MPDC placement. We tested the algorithm for a single rotor and focal source for all possible initial positions on the simulated tissue and repeated it for a random placement with a maximum of 20 possible placements at every trial. The algorithm located the AF source for 100% of trials and on average required 5.99 ± 1.92 placements to an AF source. This algorithm may be used to iteratively direct an MPDC towards an AF source and allow the AF source to be localized for customized AF ablation.

Understanding the Beat-to-Beat Variations of P-Waves Morphologies in AF Patients During Sinus Rhythm: A Scoping Review of the Atrial Simulation Studies

“…Studying the electrophysiological changes on AP and ion kinetics (Jones et al, 2012; Sanchez et al, 2012; Voigt et al, 2013, 2014) is the main subject of cell level simulations. 2D level studies target at identifying AF drivers, such as rotors and spiral waves (Becerra et al, 2014; Ganesan et al, 2016; Salmin et al, 2016; Duarte-Salazar et al, 2017; Aronis and Ashikaga, 2018) or the effect of spatial resolution on AF drivers detection (Rappel and Narayan, 2013; Roney et al, 2017). The use of patient-specific 3D models can give more insight into the mechanism of AF (Zahid et al, 2016).…”

“…In a healthy heart, the electrical pulse originates from the sinus node and spreads through the atrium (Platonov, 2012), while during an AF episode chaotic activation of atrial myocardium occurs (Yamazaki and Jalife, 2012). In the majority of the papers included in this review, AF was induced and the analysis focused on the identification of AF drivers (Ashihara et al, 2004; Martínez et al, 2014b; Tobón et al, 2014b; Ugarte et al, 2014, 2015; Felix et al, 2015; Martinez et al, 2016; Salmin et al, 2016; Roney et al, 2017; Duarte-Salazar et al, 2017) or on the study of the electrical activation during AF in general. However, analysis of the electrical activation of the remodeled atria during SR was the subject of 52 studies, as this can also improve our understanding of the pathology.…”

Simulation of Spiral Waves and Point Sources in Atrial Fibrillation with Application to Rotor Localization

“…The developed algorithm iteratively guides the MPDC from any random location that we start from, to converge at the core of the rotor. This iterative probabilistic approach is an improvement of our non-probabilistic MPDC guidance algorithm published previously [13]. …”

“…Example of homogeneous and heterogeneous rotor simulations – A. Rotor on a perfectly homogeneous tissue, B. Rotor on a heterogeneous tissue [13]. …”

Developing an Iterative Tracking Algorithm to Guide a Catheter Towards Atrial Fibrillation Rotor Sources in Simulated Fibrotic Tissue

“…For the most part, this work has focused on developing 3D electroanatomic mapping based on the electrogram characteristics from a single or multipole diagnostic catheter to locate AF sources. We have developed a fundamentally different approach that, without the need to map the entire atria, utilizes bipolar electrogram recordings obtained from a conventional circular catheter to iteratively guide the catheter towards the wave source and stop when a rotor source is detected [9]. In this paper, we performed a series of simulation experiments to validate the success of this algorithm to locate a rotor in a simulated human tissue.…”