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A murine experimental model for the mechanical behaviour of viable right‐ventricular myocardium
Author(s) -
ValdezJasso Daniela,
Simon Marc A.,
Champion Hunter C.,
Sacks Michael S.
Publication year - 2012
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2012.233015
Subject(s) - biomechanics , ventricular outflow tract , strain (injury) , mechanical load , anatomy , biomedical engineering , cardiology , materials science , medicine , composite material
Key points• Right‐ventricular (RV) function is an important determinant of cardio‐pulmonary performance. How and when RV failure occurs in disease is poorly understood. RV biomechanics provides a means to understand tissue level behavior that links cellular mechanisms to organ level phenotype. RV biomechanics has received little attention. • We developed 1) rat model for quantifying the structure and biomechanical behavior of viable and transmurally intact RV tissue, and 2) a novel analysis method for obtaining representative scalar strain‐energy function from stress‐controlled biaxial experiments. • The mechanical testing revealed a marked mechanical tissue anisotropy with the apex‐to‐outflow tract direction being the stiffer direction. • The myo‐ and collagen fibers show a preferential alignment from the apex to the RV outflow tract direction with little transmural variation. • We found a strong relationship between normal tissue microstructure and biomechanical behavior, which lays the foundation for a detailed understanding of RV remodeling in response to disease.Abstract Although right‐ventricular function is an important determinant of cardio‐pulmonary performance in health and disease, right ventricular myocardium mechanical behaviour has received relatively little attention. We present a novel experimental method for quantifying the mechanical behaviour of transmurally intact, viable right‐ventricular myocardium. Seven murine right ventricular free wall (RVFW) specimens were isolated and biaxial mechanical behaviour measured, along with quantification of the local transmural myofibre and collagen fibre architecture. We developed a complementary strain energy function based method to capture the average biomechanical response. Overall, murine RVFW revealed distinct mechanical anisotropy. The preferential alignment of the myofibres and collagen fibres to the apex‐to‐outflow‐tract direction was consistent with this also being the mechanically stiffer axis. We also observed that the myofibre and collagen fibre orientations were remarkably uniform throughout the entire RVFW thickness. Thus, our findings indicate a close correspondence between the tissue microstructure and biomechanical behaviour of the RVFW myocardium, and are a first step towards elucidating the structure–function of non‐contracted murine RVFW myocardium in health and disease.