title: Intermittent drivers anchoring to structural heterogeneities as a major pathophysiological mechanism of human persistent atrial fibrillation.
abstract: The mechanisms responsible for perpetuation of human persistent atrial fibrillation (AF) are controversial and probably vary between individuals. A wide spectrum of mechanisms have been described in experimental studies, ranging from a single localized stable (focal/reentrant) source, to multiple sources, up to diffuse bi-atrial wavelets. We characterized AF drivers in patients with persistent AF (lasting less than 1 year) using novel high resolution mapping, imaging and modelling approaches with the objective of evaluating their relationship to atrial structural heterogeneities. Using panoramic non-invasive mapping in humans, focal or reentrant sources driving AF waves were identified, originating from multiple distinct regions and exhibiting short lifespans and periodic recurrences in the same locations. The reentrant driver regions harboured long, fractionated electrograms covering most of the fibrillatory cycle lengths with varying beat-to-beat sequences suggestive of unstable trajectories attached to slow conducting heterogeneous tissue. MRI atrial imaging demonstrated that such drivers preferentially clustered at the borders of fibrotic atrial regions. In patient-specific computer simulations, sustained AF was shown to be driven by meandering transitory reentries attached to fibrosis borders expressing specific metrics in density and extent. Finally, random microstructural alterations devoid of cellular electrical changes were modelled, showing that a percolation mechanism could also explain atrial reentries and complex fractionated electrograms. These data from clinical, imaging and computational studies strongly suggest that intermittent and spatially unstable drivers anchoring to structural heterogeneities are a major pathophysiological mechanism in human persistent atrial fibrillation.
authors.affiliation: LIRYC Institute, University and CHU of Bordeaux, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Haissaguerre
authors.affiliation: LIRYC Institute, University and CHU of Bordeaux, France.
authors.forename: Ashok J
authors.initials: AJ
authors.lastname: Shah
authors.affiliation: LIRYC Institute, University and CHU of Bordeaux, France.
authors.forename: Hubert
authors.initials: H
authors.lastname: Cochet
authors.affiliation: LIRYC Institute, University and CHU of Bordeaux, France.
authors.forename: Meleze
authors.initials: M
authors.lastname: Hocini
authors.affiliation: LIRYC Institute, University and CHU of Bordeaux, France.
authors.forename: Remi
authors.initials: R
authors.lastname: Dubois
authors.affiliation: LIRYC Institute, University and CHU of Bordeaux, France.|Washington University, Department of Biomedical Engineering, St Louis, MO, 63130, USA.
authors.forename: Igor
authors.initials: I
authors.lastname: Efimov
authors.affiliation: LIRYC Institute, University and CHU of Bordeaux, France.
authors.forename: Edward
authors.initials: E
authors.lastname: Vigmond
authors.affiliation: LIRYC Institute, University and CHU of Bordeaux, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Bernus
authors.affiliation: Johns Hopkins University, Department of Biomedical Engineering, Baltimore, MD, 21218, USA.
authors.forename: Natalia
authors.initials: N
authors.lastname: Trayanova
mesh_terms: D000818:Animals; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging