Standardized static and dynamic evaluation of myocardial tissue properties

Area of Science:

• Biomedical Engineering
• Materials Science
• Cardiovascular Research

Background:

• Quantifying soft biological tissue mechanics is vital but faces challenges in validity and reproducibility.
• Standardized methodologies are needed for reliable mechanical property assessment of tissues like the myocardium.

Purpose of the Study:

• To quantify the mechanical properties of myocardial tissue.
• To investigate and establish methodologies for standardizing biological tissue testing.

Main Methods:

• Tensile testing was used to determine Young's modulus.
• Dynamic Mechanical Analysis (DMA) assessed viscoelastic properties across a frequency range of 0.5 Hz to 3.5 Hz.
• Three preconditioning methods (no load, 0.05 N preload, cyclic preload) were evaluated for tensile testing.

Main Results:

• Cyclic loading preconditioning yielded the most consistent moduli values.
• Mean Young's modulus for ovine/porcine tissue was 0.05/0.06 MPa (SD=0.02/0.03 MPa).
• Storage and loss moduli varied with frequency, and stiffness increased linearly with frequency.

Conclusions:

• Preconditioning is essential for achieving reproducible mechanical property measurements in myocardial tissue.
• Dynamic Mechanical Analysis (DMA) offers a reproducible platform for testing soft biological tissues.
• Standardized testing protocols enhance the reliability of mechanical behavior quantification in soft tissues.