Bank A J, Kaiser D R
Department of Medicine, University of Minnesota, Minneapolis, USA.
Hypertension. 1998 Aug;32(2):356-9. doi: 10.1161/01.hyp.32.2.356.
Compliance, distensibility, incremental elastic modulus (E(inc)), and pulse wave velocity are all terms used to describe the mechanical properties of arteries. Previous studies assessing the effects of smooth muscle relaxation on each of these parameters have produced conflicting results. Our laboratory has previously demonstrated that intrabrachial infusion of nitroglycerin in normal human subjects results in a large increase in brachial artery compliance without changing arterial wall stiffness as measured by E(inc). In the present study, the relationships among compliance, distensibility, E(inc), and pulse wave velocity under different levels of vascular tone are shown using data acquired by intravascular ultrasound as well as theoretical curves. We demonstrate that the effects of smooth muscle relaxation can be depicted as 2 separate steps: (1) a rightward shift to a new theoretical curve describing the relationship between 2 of the above elastic parameters that is solely due to changes in vessel geometry and (2) a shift along the new curve that is dependent on changes in wall stiffness.
顺应性、扩张性、增量弹性模量（E(inc)）和脉搏波速度都是用于描述动脉力学特性的术语。先前评估平滑肌舒张对这些参数各自影响的研究产生了相互矛盾的结果。我们实验室先前已证明，在正常人类受试者中肱动脉内输注硝酸甘油会导致肱动脉顺应性大幅增加，而通过E(inc)测量的动脉壁僵硬度并无变化。在本研究中，利用血管内超声获取的数据以及理论曲线展示了不同血管张力水平下顺应性、扩张性、E(inc)和脉搏波速度之间的关系。我们证明，平滑肌舒张的影响可描述为两个独立的步骤：（1）向右移动至一条新的理论曲线，该曲线描述上述两个弹性参数之间的关系，这完全是由于血管几何形状的变化所致；（2）沿着新曲线的移动，这取决于壁僵硬度的变化。
