Determinants of new wavefront locations in cholinergic atrial fibrillation

Atrial fibrillation (AF) wavefront dynamics are complex and difficult to interpret, contributing to uncertainty about the mechanisms that maintain AF. We aimed to investigate the interplay between rotors, wavelets, and focal sources during fibrillation. Arrhythmia wavefront dynamics were analysed fo...

Full description

Saved in:
Bibliographic Details
Published in:Europace (London, England) England), 2018-11, Vol.20 (suppl_3), p.iii3-iii15
Main Authors: Roney, Caroline H, Ng, Fu Siong, Debney, Michael T, Eichhorn, Christian, Nachiappan, Arun, Chowdhury, Rasheda A, Qureshi, Norman A, Cantwell, Chris D, Tweedy, Jennifer H, Niederer, Steven A, Peters, Nicholas S, Vigmond, Edward J
Format: Article
Language:English
Subjects:
Action Potentials
Animals
Atrial Fibrillation - diagnosis
Atrial Fibrillation - physiopathology
Atrial Function, Left
Atrial Remodeling
Cardiology and cardiovascular system
Cholinergic Fibers
Computer Simulation
Disease Models, Animal
Dogs
Fibrosis
Heart Atria - innervation
Heart Atria - pathology
Heart Rate
Human health and pathology
Life Sciences
Models, Cardiovascular
Time Factors
Voltage-Sensitive Dye Imaging
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Atrial fibrillation (AF) wavefront dynamics are complex and difficult to interpret, contributing to uncertainty about the mechanisms that maintain AF. We aimed to investigate the interplay between rotors, wavelets, and focal sources during fibrillation. Arrhythmia wavefront dynamics were analysed for four optically mapped canine cholinergic AF preparations. A bilayer computer model was tuned to experimental preparations, and varied to have (i) fibrosis in both layers or the epicardium only, (ii) different spatial acetylcholine distributions, (iii) different intrinsic action potential duration between layers, and (iv) varied interlayer connectivity. Phase singularities (PSs) were identified and tracked over time to identify rotational drivers. New focal wavefronts were identified using phase contours. Phase singularity density and new wavefront locations were calculated during AF. There was a single dominant mechanism for sustaining AF in each of the preparations, either a rotational driver or repetitive new focal wavefronts. High-density PS sites existed preferentially around the pulmonary vein junctions. Three of the four preparations exhibited stable preferential sites of new wavefronts. Computational simulations predict that only a small number of connections are functionally important in sustaining AF, with new wavefront locations determined by the interplay between fibrosis distribution, acetylcholine concentration, and heterogeneity in repolarization within layers. We were able to identify preferential sites of new wavefront initiation and rotational activity, in order to determine the mechanisms sustaining AF. Electrical measurements should be interpreted differently according to whether they are endocardial or epicardial recordings.
ISSN:1099-5129
1532-2092
DOI:10.1093/europace/euy235