Patterns of muscular strain in the embryonic heart wall

Authors

  • Brooke J. Damon,

    1. Department of Cell Biology and Anatomy, Medical University of South Carolina, Charleston, South Carolina
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    • Drs. Damon and Rémond contributed equally to this work.

  • Mathieu C. Rémond,

    1. Department of Cell Biology and Anatomy, Medical University of South Carolina, Charleston, South Carolina
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    • Drs. Damon and Rémond contributed equally to this work.

  • Michael R. Bigelow,

    1. Department of Cell Biology and Anatomy, Medical University of South Carolina, Charleston, South Carolina
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  • Thomas C. Trusk,

    1. Department of Cell Biology and Anatomy, Medical University of South Carolina, Charleston, South Carolina
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  • Wenjie Xie,

    1. Department of Mechanical Engineering, University of Rochester, Rochester, New York
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  • Renato Perucchio,

    1. Department of Mechanical Engineering, University of Rochester, Rochester, New York
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  • David Sedmera,

    1. Institute of Physiology, Centre for Cardiovascular Research, and Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
    2. Institute of Anatomy, Charles University in Prague, First Faculty of Medicine, Prague, Czech Republic
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  • Stewart Denslow,

    1. Department of Cell Biology and Anatomy, Medical University of South Carolina, Charleston, South Carolina
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  • Robert P. Thompson

    Corresponding author
    1. Department of Cell Biology and Anatomy, Medical University of South Carolina, Charleston, South Carolina
    • Department of Cell Biology and Anatomy, Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC 29425
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Abstract

The hypothesis that inner layers of contracting muscular tubes undergo greater strain than concentric outer layers was tested by numerical modeling and by confocal microscopy of strain within the wall of the early chick heart. We modeled the looped heart as a thin muscular shell surrounding an inner layer of sponge-like trabeculae by two methods: calculation within a two-dimensional three-variable lumped model and simulated expansion of a three-dimensional, four-layer mesh of finite elements. Analysis of both models, and correlative microscopy of chamber dimensions, sarcomere spacing, and membrane leaks, indicate a gradient of strain decreasing across the wall from highest strain along inner layers. Prediction of wall thickening during expansion was confirmed by ultrasonography of beating hearts. Degree of stretch determined by radial position may thus contribute to observed patterns of regional myocardial conditioning and slowed proliferation, as well as to the morphogenesis of ventricular trabeculae and conduction fascicles. Developmental Dynamics 238:1535–1546, 2009. © 2009 Wiley-Liss, Inc.

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