An image-based model of atrial muscular architecture effects of structural anisotropy on electrical activation

Jichao Zhao, Timothy D. Butters, Henggui Zhang, Andrew J. Pullan, Ian J. LeGrice, Gregory B. Sands, Bruce H. Smaill

    Research output: Contribution to journalArticlepeer-review

    Abstract

    Background-Computer models that capture key features of the heterogeneous myofiber architecture of right and left atria and interatrial septum provide a means of investigating the mechanisms responsible for atrial arrhythmia. The data necessary to implement such models have not previously been available. The aims of this study were to characterize surface geometry and myofiber architecture throughout the atrial chambers and to investigate the effects of this structure on atrial activation. Methods and Results-Atrial surface geometry and myofiber orientations were reconstructed in 3D at 50×50×50- μm 3 resolution from serial images acquired throughout the sheep atrial chambers. Myofiber orientations were determined by Eigen-analysis of the structure tensor. These data have been incorporated into an anatomic model that provides the first quantitative representation of myofiber architecture throughout the atrial chambers. By simulating activation on this 3D structure, we have confirmed the roles of specialized myofiber tracts such as the crista terminalis, pectinate muscles, and the Bachman bundle on the spread of activation from the sinus node. We also demonstrate how the complex myocyte arrangement in the posterior left atrium contributes to activation time dispersion adjacent to the pulmonary veins and increased vulnerability to rhythm disturbance generated by ectopic stimuli originating in the pulmonary vein sleeves. Conclusions-We have developed a structurally detailed, image-based model of atrial anatomy that provides deeper understanding of the role that myocyte architecture plays in normal and abnormal atrial electric function. © 2012 American Heart Association, Inc.
    Original languageEnglish
    Pages (from-to)361-370
    Number of pages9
    JournalCirculation: Arrhythmia and Electrophysiology
    Volume5
    Issue number2
    DOIs
    Publication statusPublished - Apr 2012

    Keywords

    • Atrial fibrillation
    • Atrial myoarchitecture
    • Computer model
    • Electric simulation
    • Fiber orientation

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