Heart and Vascular Institute, Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
J Physiol. 2012 Sep 15;590(18):4571-84. doi: 10.1113/jphysiol.2012.233015. Epub 2012 Jul 30.
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.
虽然右心室功能是健康和疾病中心肺功能的重要决定因素，但右心室心肌的力学行为却相对较少受到关注。我们提出了一种新的实验方法，用于量化完整、存活的右心室心肌的力学行为。我们分离了 7 个鼠右心室游离壁（RVFW）标本，并测量了它们的双轴力学性能，同时还定量分析了局部的心肌纤维和胶原纤维结构。我们开发了一种补充的应变能函数方法来捕捉平均生物力学响应。总的来说，鼠 RVFW 表现出明显的力学各向异性。心肌纤维和胶原纤维优先沿心尖至流出道方向排列，这与力学上更硬的轴一致。我们还观察到，心肌纤维和胶原纤维的取向在整个 RVFW 厚度上非常均匀。因此，我们的发现表明 RVFW 心肌的组织微观结构和生物力学行为之间存在密切的对应关系，这是阐明健康和疾病状态下非收缩性鼠 RVFW 心肌结构-功能的第一步。
