Armentano R L, Cabrera Fischer E I, Barra J G, Levenson J A, Simon A C, Pichel R H
Basic Sciences Research Center, University Institute of Biomedical Sciences, Favaloro Foundation, Buenos Aires, Argentina.
Med Prog Technol. 1994;20(1-2):91-9.
A description of the arterial wall elastic properties comprehends both collagen and elastin, clearly shown in a biphasic stress-strain relationship. From chronically instrumented conscious dogs, aortic pressure-diameter curves can be obtained in a single beat, which is impossible to perform in human beings. In control conditions, the collagen fibers are almost not distended and the resistance to stretch is mainly supported by the elastin fibers. Therefore, the mechanical properties of the aorta are almost purely elastic in the basal beat to beat conditions. In this study we propose and test five indexes, which include as variables: systolic, diastolic and mean arterial pressure and diameter; besides, arterial compliance and pressure-strain elastic modulus as suggested to evaluate the elastic behaviour of the elastic fibers. This data can be easily obtained by non-invasive methods, such as Doppler-ultrasound techniques and auscultative esphygmomanometrical measurements, while the indexes evaluated can be retrieved from a single beat evaluation. Of three measurements performed in chronically instrumented conscious dogs on different days, one of these indexes, the ME5 = [formula: see text] x Rdias proved to be an accurate and reliable parameter to evaluate the mechanical behaviour of arteries. This kind of parameter may be useful for research and evaluation of several diseases that markedly alter the arterial wall compliance.
动脉壁弹性特性的描述包括胶原蛋白和弹性蛋白，这在双相应力-应变关系中清晰可见。从长期植入仪器的清醒犬身上，可以在单次搏动中获得主动脉压力-直径曲线，而这在人类中是无法做到的。在对照条件下，胶原纤维几乎不被拉伸，对拉伸的阻力主要由弹性纤维承担。因此，在基础的搏动条件下，主动脉的力学特性几乎是纯弹性的。在本研究中，我们提出并测试了五个指标，这些指标的变量包括：收缩压、舒张压、平均动脉压和直径；此外，还有如所建议的用于评估弹性纤维弹性行为的动脉顺应性和压力-应变弹性模量。这些数据可以通过非侵入性方法轻松获得，如多普勒超声技术和听诊式血压测量，而所评估的指标可以从单次搏动评估中获取。在不同日期对长期植入仪器的清醒犬进行的三次测量中，这些指标之一，即ME₅ = [公式：见原文]×R舒张，被证明是评估动脉力学行为的准确可靠参数。这种参数可能对研究和评估几种显著改变动脉壁顺应性的疾病有用。
