Role of fiber orientation in atrial arrythmogenesis

Research output: Contribution to journalConference articlepeer-review

Authors

  • Sanjay Kharche
  • Simon Castro
  • Belvin Thomas
  • Michael Colman
  • Jonathan Jarvis
  • Bruce Smaill
  • Henggui Zhang
  • Jichao Zhao

Colleges, School and Institutes

External organisations

  • University of Manchester
  • University of Exeter
  • Liverpool John Moores University
  • University of Auckland
  • Research Institute for Sport and Exercise Sciences

Abstract

Electrical wave-front propagation in the atria is determined largely by local fiber orientation. Recent study suggests that atrial fibrillation (AF) progresses with enhanced anisotropy. In this work, a 3D rabbit atrial anatomical model at 20 × 20 × 20 μm3 resolution with realistic fiber orientation was constructed based on the novel contrast-enhanced micro-CT imaging. The Fenton-Karma cellular activation model was adapted to reproduce rabbit atrial action potential period of 80 ms. Diffusivities were estimated for longitudinal and transverse directions of the fiber orientation respectively. Pacing was conducted in the 3D anisotropic atrial model with a reducing S2 interval to facilitate initiation of atrial arrhythmia. Multiple simulations were conducted with varying values of diffusion anisotropy and stimulus locations to evaluate the role of anisotropy in initiating AF. Under physiological anisotropy conditions, a rapid right atrial activation was followed by the left atrial activation. Excitation waves reached the atrio-ventricular border where they terminated. Upon reduction of conduction heterogeneity, re-entry was initiated by the rapid pacing and the activation of both atrial chambers was almost simultaneous. Myofiber orientation is an effective mechanism for regulating atrial activation. Modification of myoarchitecture is proarrhythmic.

Details

Original languageEnglish
Article number7043224
Pages (from-to)1041-1044
Number of pages4
JournalComputing in Cardiology
Volume41
Issue numberJanuary
Publication statusPublished - 2014
Event41st Computing in Cardiology Conference, CinC 2014 - Cambridge, United States
Duration: 7 Sep 201410 Sep 2014