The Interventricular Septum Is Biomechanically Distinct from the Ventricular Free Walls

Autor: Michael Nguyen-Truong, Wenqiang Liu, Courtney Doherty, Kristen LeBar, Kevin Labus, Christian Puttlitz, Jeremiah Easley, Eric Monnet, Adam Chicco, Zhijie Wang
Rok vydání: 2021
Předmět:
Zdroj: Bioengineering; Volume 8; Issue 12; Pages: 216
Bioengineering, Vol 8, Iss 216, p 216 (2021)
Bioengineering
ISSN: 2306-5354
DOI: 10.3390/bioengineering8120216
Popis: The interventricular septum contributes to the pumping function of both ventricles. However, unlike the ventricular wall, its mechanical behavior remains largely unknown. To fill the knowledge gap, this study aims to characterize the biaxial and transmural variation of the mechanical properties of the septum and compare it to the free walls of the left and right ventricles (LV/RV). Fresh hearts were obtained from healthy, adult sheep. The septal wall was sliced along the mid-line into two septal sides and compared to the epicardial layers of the LV- and RV-free walls. Biaxial tensile mechanical tests and constitutive modeling were performed to obtain the passive mechanical properties of the LV- and RV-side of the septum and ventricular walls. We found that both sides of the septum were significantly softer than the respective ventricular walls, and that the septum presented significantly less collagen than the ventricular walls. At low strains, we observed the symmetric distribution of the fiber orientations and a similar anisotropic behavior between the LV-side and RV-side of the septum, with a stiffer material property in the longitudinal direction, rather than the circumferential direction. At high strains, both sides showed isotropic behavior. Both septal sides had similar intrinsic elasticity, as evidenced by experimental data and constitutive modeling. These new findings offer important knowledge of the biomechanics of the septum wall, which may deepen the understanding of heart physiology.
Databáze: OpenAIRE
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