Application Note | ElastoSens™ Bio
Measuring mechanical properties of heart tissue using ElastoSens™ Bio
Introduction
The heart’s ability to pump blood depends not only on its electrical activity but also on the mechanical properties of its tissue. These properties—ranging from elasticity to stiffness and viscoelasticity—govern how the myocardium stretches, contracts, and relaxes across the cardiac cycle. Subtle changes in these mechanics can signal early disease, while more pronounced alterations impair the heart’s ability to fill and eject blood. By studying them, scientists and clinicians can better understand how a healthy heart functions, detect early signs of disease, and design therapies that restore or preserve performance.
Key mechanical properties of the heart
Elasticity
Elasticity reflects the myocardium’s ability to return to its original shape after deformation. It is essential for diastolic filling, allowing the ventricles to accommodate incoming blood and then recoil efficiently for the next contraction.
Stiffness
Stiffness represents resistance to deformation, often quantified through parameters like the elastic modulus or pressure–volume relationships. It varies dynamically across the cardiac cycle, with low stiffness during diastole and higher stiffness during systole.
Compliance
Compliance, the inverse of stiffness, describes the heart’s ability to expand when filled. Reduced compliance limits filling capacity and is a hallmark of diastolic dysfunction.
Viscoelasticity
The heart exhibits both elastic and viscous behavior, meaning its response depends not only on the degree of stretch but also on the rate of deformation. This viscoelasticity influences how the myocardium dissipates or stores energy during contraction and relaxation.
Anisotropy
Because of its complex fiber architecture, the myocardium is anisotropic—its mechanical behavior varies depending on the direction of applied force. This anisotropy contributes to efficient wall thickening and coordinated pumping.
Relationship between diseases and mechanical properties of heart tissue
Heart Failure with Preserved Ejection Fraction (HFpEF)
HFpEF is strongly associated with increased myocardial stiffness and reduced compliance. These changes impair diastolic filling, limiting the heart’s ability to meet circulatory demands despite normal ejection fraction.
Fibrosis
Cardiac fibrosis, characterized by excessive collagen deposition, stiffens the extracellular matrix and alters anisotropy. This remodeling disrupts normal mechanics, contributing to both systolic and diastolic dysfunction.
Ischemia/Reperfusion injury
During ischemia and subsequent reperfusion, myocardial stiffness changes dynamically. Shear wave elastography studies show altered systolic and diastolic stiffness, reflecting impaired contractility and relaxation in injured tissue.
Dilated cardiomyopathy
In dilated cardiomyopathy, changes in passive and active mechanical properties—including increased compliance and altered viscoelasticity—lead to chamber dilation, reduced contractility, and progressive heart failure.
How heart tissue mechanics are assessed
In Vivo techniques (Clinics)
Clinically, heart stiffness can be assessed using both invasive and non-invasive techniques. Pressure–volume loop analysis via catheterization remains the gold standard for chamber stiffness. Non-invasive approaches are increasingly common, including shear wave elastography (SWE), which tracks wave propagation in the myocardium, and advanced imaging tools such as magnetic resonance elastography (MRE) and acoustic radiation force impulse imaging (ARFI). These methods provide valuable insights into diastolic and systolic function and are key for early detection of disease-related changes.
Ex Vivo techniques (Research)
In research, ex vivo methods enable detailed characterization of cardiac tissue mechanics. Common instruments include tensile testing, shear rheometry, and indentation (nano- to micro-scale), applied from isolated cells to whole-heart samples. These techniques reveal elasticity, viscosity, and viscoelastic behavior under controlled conditions, helping researchers link molecular changes to overall myocardial mechanics.
Case study: Heart tissue mechanical characterization with ElastoSens™ Bio
In the field of heart biomechanics, the ElastoSens™ Bio offers an advanced approach to ex vivo testing. This instrument enables continuous and non-destructive measurement of viscoelastic properties, ensuring that tissue integrity is maintained throughout experiments. Its technology provides accurate characterization of soft cardiac samples and supports repeated testing over long periods under different environmental conditions, expanding the information available beyond traditional mechanical assays.
To demonstrate the capabilities of the ElastoSens™ Bio, we performed an ex vivo study on heart tissue samples. The following section describes the materials and methods applied in this experiment, followed by the results, showcasing a practical example of the instrument’s application.
Material and methods
Hearts from pork and sheep were obtained from a local farm. Tissue specimens with an approximate cylindrical shape (23 mm internal diameter, variable height) were excised using a biopsy-like punch. Each sample was carefully positioned in the macro holder of the ElastoSens™ Bio instrument. Measurements were conducted at room temperature, with each sample tested for one minute.
The instrument provided real-time viscoelastic parameters, including the shear storage modulus (G′) and the damping ratio (Tan𝛿). For each condition, results were expressed as the mean values obtained from five independent samples, extracted from the same anatomical location in five different hearts (n=5).
Figure 1. Heart tissue sample in the ElastoSens™ Bio macro holder for non-destructive mechanical characterization.
Results and discussion
Using the ElastoSens™ Bio non-destructive testing system, Figure 2 shows that pig heart tissue exhibited a higher shear storage modulus (G′ = 7.8 ± 1.3 kPa) compared to sheep (4.1 ± 1.3 kPa), indicating greater stiffness and elastic energy storage. Conversely, sheep tissue displayed a higher damping ratio (Tanδ = 0.42 ± 0.05 vs. 0.36 ± 0.05), reflecting greater viscous energy dissipation. These species-specific viscoelastic properties highlight that pig myocardium is mechanically stiffer, while sheep myocardium is more dissipative.
Our values for pig heart are consistent with those reported by Kolipaka et al. (2010) and Nenadic et al. (2009), who measured porcine myocardium using magnetic resonance elastography and shearwave vibrometry, reporting shear moduli in the range of 7.69–12.7 kPa. For sheep myocardium, biaxial tensile testing reported equivalent shear storage moduli in the range of 4.4–10.2 kPa, with an average of approximately 6.5 kPa (Pandelani et al., 2025), reflecting regional and directional variation across the ventricles. Overall, the ElastoSens™ Bio enables ex vivo tissue measurements with minimal handling, under controlled hydration and loading conditions. This controlled setup reduces external sources of variability and captures the intrinsic viscoelastic response of myocardial tissue.
Figure 2: Viscoelastic properties of heart tissue for sheep and pig: shear storage modulus (G′) (left) and damping ratio (Tan𝛿) (right) obtained with the ElastoSens™ Bio non-destructive testing system (mean ± SD, n=5).
Conclusions and perspectives
The mechanical properties of heart tissue, including elasticity, stiffness, viscoelasticity, and anisotropy, are central to understanding both physiological function and pathological remodeling. The present study confirms that non-destructive viscoelastic testing with the ElastoSens™ Bio allows reliable measurement of heart tissue mechanics, capturing key parameters such as shear storage modulus (G′) and damping ratio (Tan𝛿). This approach ensures precise and reproducible data, providing a strong foundation for comparative studies across species and conditions.
Beyond these results, the ElastoSens™ Bio offers unique advantages for cardiovascular and biomaterials research:
- Simple preparation and setup minimize handling and preserve myocardial hydration and architecture.
- High sensitivity and repeatability ensure consistent measurements across different cardiac regions (atria, ventricles, septum), capturing intra-organ variability.
- Cross-species benchmarking allows translational studies by directly comparing heart mechanics in animal models and humans.
- Platform versatility supports testing of diverse cardiac tissues and biomaterials under identical conditions, useful for developing heart patches, scaffolds, or valve substitutes.
- Engineered tissue applications benefit from non-destructive, repeated measurements that capture the dynamic evolution of bioengineered myocardial constructs.
- Controlled incubation and repeated testing make it possible to monitor changes in viscoelastic properties over time, whether due to ischemia, pharmacological interventions, or progressive disease.
Together, these capabilities position the ElastoSens™ Bio as a valuable tool for advancing cardiac tissue research, comparative physiology, and the development of engineered biomaterials.
References
Villalobos Lizardi, J. C., Baranger, J., Nguyen, M. B., Asnacios, A., Malik, A., Lumens, J., … & Villemain, O. (2022). A guide for assessment of myocardial stiffness in health and disease. Nature Cardiovascular Research, 1(1), 8-22.
Emig, R., Zgierski-Johnston, C. M., Timmermann, V., Taberner, A. J., Nash, M. P., Kohl, P., & Peyronnet, R. (2021). Passive myocardial mechanical properties: meaning, measurement, models. Biophysical reviews, 13(5), 587-610.
Caenen, A., Keijzer, L., Bézy, S., Duchenne, J., Orlowska, M., Van Der Steen, A. F., … & Vos, H. J. (2023). Continuous shear wave measurements for dynamic cardiac stiffness evaluation in pigs. Scientific Reports, 13(1), 17660.
Kolipaka, A., Araoz, P. A., McGee, K. P., Manduca, A., & Ehman, R. L. (2010). Magnetic resonance elastography as a method for the assessment of effective myocardial stiffness throughout the cardiac cycle. Magnetic Resonance in Medicine, 64(3), 862–870.
Nenadic, I., Urban, M. W., & Greenleaf, J. F. (2009). Ex vivo measurements of myocardial viscoelasticity using shearwave dispersion ultrasound vibrometry (SDUV). Proceedings of the IEEE Engineering in Medicine and Biology Society, 2895–2898.
Pandelani, T., Mashosho, E., Walker, C., Scheffer, C., & Franz, T. (2025). Passive biaxial mechanical and microstructural characterization of adult ovine heart ventricles. Frontiers in Bioengineering and Biotechnology, 13, 1500585.
Discover how our technology non-destructively measures the viscoelastic properties of soft biomaterials and tissues using micro-volumes of samples
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