• Triggers and maintenance of id...

*Result*: Triggers and maintenance of idiopathic atrial fibrillation: A multiscale computational simulation study.

Title:
Triggers and maintenance of idiopathic atrial fibrillation: A multiscale computational simulation study.
Authors:
Xin L; Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Shenzhen, 518055, China., Haiying L; The University of Hong Kong-Shenzhen Hospital, Shenzhen, 518053, China., Yanhong C; The University of Hong Kong-Shenzhen Hospital, Shenzhen, 518053, China., Shiqi Y; Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Shenzhen, 518055, China., Linsheng H; Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Shenzhen, 518055, China., Jian W; Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Shenzhen, 518055, China. Electronic address: wuj@sz.tsinghua.edu.cn.
Source:
Computer methods and programs in biomedicine [Comput Methods Programs Biomed] 2026 Feb 01; Vol. 274, pp. 109173. Date of Electronic Publication: 2025 Nov 19.
Publication Type:
Journal Article
Language:
English
Journal Info:
Publisher: Elsevier Scientific Publishers Country of Publication: Ireland NLM ID: 8506513 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1872-7565 (Electronic) Linking ISSN: 01692607 NLM ISO Abbreviation: Comput Methods Programs Biomed Subsets: MEDLINE
Imprint Name(s):
Publication: Limerick : Elsevier Scientific Publishers
Original Publication: Amsterdam : Elsevier Science Publishers, c1984-
MeSH Terms:
Atrial Fibrillation*/physiopathology , Atrial Fibrillation*/etiology , Computer Simulation*, Humans ; Action Potentials ; Heart Atria/physiopathology ; Models, Cardiovascular ; Heart Conduction System/physiopathology
Contributed Indexing:
Keywords: Atrial computational model; Chaotic electrical activity; Electrical remodeling; Idiopathic atrial fibrillation; Spiral wave
Entry Date(s):
Date Created: 20251130 Date Completed: 20251207 Latest Revision: 20251207
Update Code:
20260130
DOI:
10.1016/j.cmpb.2025.109173
PMID:
41319412
Database:
MEDLINE

*Further Information*

*Background and Objective: Idiopathic atrial fibrillation (IAF) is linked to electrical remodeling, yet prospective clinical cohort data isolating the individual contributions of candidate risk factors remain scarce. To address the gap, we used in-silico simulations to delineate the mechanisms and interactions underlying IAF.
Methods: We built a multi-scale atrial computational model on a 3D atrial anatomy integrating ion-channel kinetics, cellular electrophysiology, and tissue-level propagation. Atrial tissue conductivity (ATC), atrial effective refractory period (AERP), and sinus cycle length (SCL) were systematically varied at 6, 4, and 4 levels, respectively, within physiologic ranges. We recorded parameter sets that precipitated IAF and quantified dynamics by complexity, stability, and spatial disorder.
Results: In our simulations, ATC was represented by the diffusion coefficient D <subscript>scalar</subscript> , and the action potential duration at -60 mV (APD-60mV) served as a surrogate for AERP. At SCL = 1000 ms, IAF initiated only when APD-60mV = 94 ms and D <subscript>scalar</subscript> ≤ 0.0002 mm <sup>2</sup> /ms. With SCL shortening, the APD-60mV threshold for initiation decreased. SCL modulated susceptibility but was not sufficient alone. If either the AERP or ATC criterion was unmet, IAF did not initiate at any SCL. After initiation, both slow conduction and high frequency pacing increased arrhythmic complexity (spiral-wave count +63% and +129%); high frequency pacing enhanced stability (spiral-wave lifetimes up to +48%), whereas slow conduction worsened spatial disorder (organization index -27%). Spiral waves preferentially clustered along the interatrial septum.
Conclusions: IAF initiation requires both shortened AERP and reduced ATC, while maintenance is promoted by high-frequency pacing and slowed conduction. The interatrial septum emerges as a leading non-pulmonary-vein source. These findings provide mechanistic insight into IAF initiation and persistence and may inform early prevention.
(Copyright © 2025 Elsevier B.V. All rights reserved.)*

*Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.*