Rotor mapping and ablation to treat atrial fibrillation

Abstract

Purpose of review Rotors have long been postulated to drive atrial fibrillation, but evidence has been limited to animal models. This changed recently with the demonstration using focal impulse and rotor modulation (FIRM) mapping that rotors act as human atrial fibrillation sources. This mechanistic approach to diagnosing the causes of atrial fibrillation in individual patients has been supported by substantially improved outcomes from FIRM-guided ablation, resulting in increased attention to rotors as therapeutic targets. Recent findings In this review, we outline the pathophysiology of rotors in animal and in-silico studies of fibrillation, and how this motivated FIRM mapping in humans. We highlight the characteristics of rotors in human atrial fibrillation, now validated by several techniques, with discussion on similar and discrepant findings between techniques. The interventional approaches to eliminate atrial fibrillation rotors are explained and the ablation results in latest studies using FIRM are discussed. Summary We propose that mapping localized sources for human atrial fibrillation, specifically rotors, is moving the field towards a unifying hypothesis that explains several otherwise contradictory observations in atrial fibrillation management. We conclude by suggesting areas of potential research that may reveal more about these critical sites and how these may lead to better and novel treatments for atrial fibrillation.

2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation

“… 644 Ablation of non-PV focal triggers identified via isoproterenol challenge, ablation of atrial scarred regions, or ablation of localized rotational activations (so-called rotational activity) have also been reported to have benefit over PVI alone. 140 , 534 , 538 , 645 It appears that regardless of which target is chosen, complete local elimination of the target should be the goal, so as not to leave behind partially ablated tissue that could serve as a site for future AT recurrence. The best method of ablating a localized rotational activation is as yet unclear.…”

The contact electrogram and its architectural determinants in atrial fibrillation

“…inter-electrode spacing (Yamada, Murakami, Okada, et al, 2006;Arentz, Haegeli, Sanders, et al, 2007;Schmitt, Ndrepepa & Weber, 2002). However the addition of phase mapping, unipolar electrogram recording, physiological filtering to identify principal components (Zaman, Peters & Narayan, 2015) and a planimetric display offer a deceptively simple propagation map often showing one or two rotors, with 30% located in the right atrium. These findings have caused controversy in the field as the algorithms used are proprietary (Topera Medical Inc, Menlo Park, USA) but are being reproduced by other groups using FIRM technology outside of the index centre (Miller, Kowal, Swarup, et al, 2014;Lin, Kuck, Ouyang, et al, 2014;Rashid & Sweeney, 2015;Tomassoni, Duggal, Muir, et al, 2015;Miller, Kalra, Das, et al, 2017).…”

Focal impulse and rotor modulation of atrial rotors during atrial fibrillation leads to organization of left atrial activation as reflected by waveform morphology recurrence quantification analysis and organizational index

“…Identification and ablation of extrapulmonary drivers of atrial fibrillation (AF) may improve maintenance of sinus rhythm after catheter ablation. 1 Over the past several years, focal impulse and rotor modulation (FIRM) has emerged as an adjunctive ablation technique to sites of organized rotational activity during AF ablation. However, results following FIRM have been highly variable with anywhere between 17% and 80% freedom from AF at 1 year.…”