Chen H I, Hu C T, Chang K C
Department of Physiology and Cardiovascular Research Laboratory, Tzu Chi College of Medicine, Hualien, Taiwan, Republic of China.
Chin J Physiol. 1996;39(1):49-55.
In long-term hypertension, hemodynamic alterations are associated with functional and structural changes in the cardiovascular system. The technique of arterial impedance spectral analysis has long been used to characterize the arterial hemodynamics of steady and pulsatile components in human hypertension. Although rats with spontaneous hypertension (SHR) are the most common model for studies of primary hypertension, characterization of complete hemodynamic parameters has not been accomplished in this animal model. In the present experiment, aortic flow and pressure waves were recorded in anesthetized, open-chest and ventilated rats. Arterial impedance spectral analysis was employed to obtain steady and pulsatile hemodynamic parameters. A total of 26 SHRs (22-24 wk) and 22 age-matched normotensive WKYs was used. The purpose was to provide a comprehensive analysis of arterial hemodynamics in rats with established hypertension. The SHR had higher arterial pressure (50% increase over the control) than WKY. The total peripheral resistance was elevated by 57%. Stroke volume was decreased by 23% and heart rate increased by 18% without a significant change in cardiac output. The characteristic impedance was increased by 43%, while arterial compliance was decreased by 52%. There were also big rises in ventricular work and wave reflection. The results provide quantitative analysis of the alteration in arterial hemodynamics of steady and pulsatile components in rats with established hypertension. In long-term hypertension, the hemodynamics reflect functional abnormalities in the resistance and Windkessel vessels.
在长期高血压中，血流动力学改变与心血管系统的功能和结构变化相关。动脉阻抗频谱分析技术长期以来一直用于表征人类高血压中稳定和搏动性成分的动脉血流动力学。虽然自发性高血压大鼠（SHR）是原发性高血压研究中最常用的模型，但在这种动物模型中尚未完成完整血流动力学参数的表征。在本实验中，在麻醉、开胸和通气的大鼠中记录主动脉血流和压力波。采用动脉阻抗频谱分析来获得稳定和搏动性血流动力学参数。总共使用了26只SHR（22 - 24周龄）和22只年龄匹配的正常血压WKY大鼠。目的是对已患高血压大鼠的动脉血流动力学进行全面分析。SHR的动脉压比WKY高（比对照组增加50%）。总外周阻力升高了57%。每搏量减少了23%，心率增加了18%，心输出量无显著变化。特征阻抗增加了43%，而动脉顺应性降低了52%。心室功和波反射也有大幅升高。结果提供了对已患高血压大鼠稳定和搏动性成分动脉血流动力学改变的定量分析。在长期高血压中，血流动力学反映了阻力血管和弹性贮器血管的功能异常。
