Granger causality connectivity analysis of persistent atrial fibrillation dynamics reveals posterior wall mechanistic insights
File(s)
Article in Press
Author(s)
Type
Journal Article
Abstract
Background:
Adjunctive posterior wall isolation (PWI) to pulmonary vein isolation (PVI) has not demonstrated convincing benefit during atrial fibrillation (AF) ablation. To provide mechanistic insight for null PWI trials we undertook Granger Causality (GC) analysis of non-contact left atrial electro-anatomical maps.
Objective:
To apply GC to intracardiac electrograms to uncover patient specific AF dynamics and describe a proof-of-concept approach to targeted PWI following PVI.
Methods:
A prospective cohort study was undertaken at Royal Brompton Hospital. Consecutive patients undergoing PVI with non-contact mapping (AcQmap; Acutus Medical) before and after PVI were included.
Results:
In 21 patients, Causality Pairing Index, a GC measure of organisation, was unchanged post PVI; overall 0.087±0.012 vs. 0.086±0.015, p = 0.64, or by region (posterior wall (PW); 0.084±0.020 vs 0.079±0.017, p = 0.20, rest of LA 0.087±0.013 vs 0.086±0.016, p = 0.80). Directional dispersion, quantifying conduction heterogeneity, was lower in the PW compared to the rest of the left atrium (LA) (0.093±0.036 vs 0.11±0.043, p = 0.017) and increased following PVI (0.093±0.036 vs 0.12±0.043, p = 0.045), while there was no change in the rest of the LA (0.11±0.034 vs 0.11±0.030, p =0.52). PW net outflow overall decreased following PVI (pre -0.0086±0.047 vs -0.033±0.054, p=0.011) with a minority of patients exhibiting a net positive outflow from the posterior wall.
Conclusion:
GC provides mechanistic insight into the null trials for PWI and identifies a minority of patients that may benefit. GC is positioned as a clinical decision tool to guide personalised persistent AF ablation strategies.
Adjunctive posterior wall isolation (PWI) to pulmonary vein isolation (PVI) has not demonstrated convincing benefit during atrial fibrillation (AF) ablation. To provide mechanistic insight for null PWI trials we undertook Granger Causality (GC) analysis of non-contact left atrial electro-anatomical maps.
Objective:
To apply GC to intracardiac electrograms to uncover patient specific AF dynamics and describe a proof-of-concept approach to targeted PWI following PVI.
Methods:
A prospective cohort study was undertaken at Royal Brompton Hospital. Consecutive patients undergoing PVI with non-contact mapping (AcQmap; Acutus Medical) before and after PVI were included.
Results:
In 21 patients, Causality Pairing Index, a GC measure of organisation, was unchanged post PVI; overall 0.087±0.012 vs. 0.086±0.015, p = 0.64, or by region (posterior wall (PW); 0.084±0.020 vs 0.079±0.017, p = 0.20, rest of LA 0.087±0.013 vs 0.086±0.016, p = 0.80). Directional dispersion, quantifying conduction heterogeneity, was lower in the PW compared to the rest of the left atrium (LA) (0.093±0.036 vs 0.11±0.043, p = 0.017) and increased following PVI (0.093±0.036 vs 0.12±0.043, p = 0.045), while there was no change in the rest of the LA (0.11±0.034 vs 0.11±0.030, p =0.52). PW net outflow overall decreased following PVI (pre -0.0086±0.047 vs -0.033±0.054, p=0.011) with a minority of patients exhibiting a net positive outflow from the posterior wall.
Conclusion:
GC provides mechanistic insight into the null trials for PWI and identifies a minority of patients that may benefit. GC is positioned as a clinical decision tool to guide personalised persistent AF ablation strategies.
Date Issued
2025-05-11
Date Acceptance
2025-05-04
Citation
Heart Rhythm O2, 2025
ISSN
2666-5018
Publisher
Elsevier
Journal / Book Title
Heart Rhythm O2
Copyright Statement
© 2025 Heart Rhythm Society. Published by Elsevier Inc. This version is available open access under a CC-BY License (https://creativecommons.org/licenses/by/4.0/)
License URL
Identifier
10.1016/j.hroo.2025.05.002
Publication Status
Published online
Date Publish Online
2025-05-11