title: Standardized static and dynamic evaluation of myocardial tissue properties.
abstract: Quantifying the mechanical behaviors of soft biological tissues is of considerable research interest. However, validity and reproducibility between different researchers and apparatus is questionable. This study aims to quantify the mechanical properties of myocardium while investigating methodologies that can standardize biological tissue testing.
  
  
  
  Tensile testing was performed to obtain Young's modulus and a dynamic mechanical analysis (DMA) determined the viscoelastic properties. A frequency range of 0.5 Hz (30bpm) to 3.5 Hz (210bpm) was analyzed. For tensile testing three different preconditioning settings were tested: no load, 0.05 N preload, and a cyclic preload at 2.5% strain and 10 cycles. Samples were placed in saline and tested at 37 °C. Five ovine and five porcine hearts were tested.
  
  
  
  Cyclic loading results in the most consistent moduli values. The modulus of ovine/porcine tissue was mean = 0.05/.06 MPa, SD = 0.02/0.03 MPa. The storage/loss modulus varied from = 0.02/0.003 MPa at 0.5 Hz to 0.04/0.008 MPa at 3.5 Hz; Stiffness increases linearly from 400 to 800 N m-1with a tan delta around 0.175.
  
  
  
  Static analysis of the mechanical properties of myocardial tissue confirms that; preconditioning is necessary for reproducibility, and DMA provides a platform for reproducible testing of soft biological tissues.
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Rosebrugh Building (RS), 164 College Street, Room 407, Toronto, Ontario M5S 3G9, Canada.
authors.forename: Sherif
authors.initials: S
authors.lastname: Ramadan
authors.forename: Narinder
authors.initials: N
authors.lastname: Paul
authors.forename: Hani E
authors.initials: HE
authors.lastname: Naguib
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D055119:Elastic Modulus; D006321:Heart / Q000033:anatomy & histology / Q000502:physiology*; D008422:Materials Testing; D012756:Sheep; D013552:Swine; D013718:Tensile Strength; D023822:Tissue Engineering; D014783:Viscosity