Li Ye, Gu Haotian, Fok Henry, Alastruey Jordi, Chowienczyk Philip
From the British Heart Foundation Centre (Y.L., H.G., H.F., P.C.) and Division of Imaging Sciences and Biomedical Engineering (J.A.), King's College London, United Kingdom.
Hypertension. 2017 Feb;69(2):375-381. doi: 10.1161/HYPERTENSIONAHA.116.08089. Epub 2016 Dec 5.
We tested the hypothesis that increased pulse wave reflection and altered backward waveform morphology contribute to increased pulse pressure in subjects with higher pulse pressure compared with lower pulse pressure and to actions of vasoactive drugs to increase pulse pressure. We examined the relationship of backward to forward wave morphology in 158 subjects who were evaluated for hypertension (including some normotensive subjects) divided into 3 groups by central pulse pressure: group 1, 33±6.5 mm Hg; group 2, 45±4.1 mm Hg; and group 3, 64±12.9 mm Hg (means±SD) and in healthy normotensive subjects during administration of inotropic and vasomotor drugs. Aortic pressure and flow in the aortic root were estimated by carotid tonometry and Doppler sonography, respectively. Morphology of the backward wave relative to the forward wave was similar in subjects in the lowest and highest tertiles of pulse pressure. Similar results were seen with the inotropic, vasopressor and vasodilator drugs, dobutamine, norepinephrine, and phentolamine, with the backward wave maintaining a constant ratio to the forward wave. However, nitroglycerin, a drug with a specific action to dilate muscular conduit arteries, reduced the amplitude of the backward wave relative to the forward wave from 0.26±0.018 at baseline to 0.19±0.019 during nitroglycerin 30 μg/min IV (P<0.01). These results are best explained by an approximately constant amount of reflection of the forward wave from the peripheral vasculature. The amount of reflection can be modified by dilation of peripheral muscular conduit arteries but contributes little to increased pulse pressure in hypertension.
与脉压较低的受试者相比，脉压较高的受试者中脉波反射增加和逆向波形形态改变会导致脉压升高，以及血管活性药物升高脉压的作用。我们在158名接受高血压评估的受试者（包括一些血压正常的受试者）中研究了逆向波与正向波形态的关系，这些受试者按中心脉压分为3组：第1组，33±6.5 mmHg；第2组，45±4.1 mmHg；第3组，64±12.9 mmHg（均值±标准差），并在健康血压正常的受试者使用正性肌力药和血管舒缩药期间进行了研究。分别通过颈动脉张力测定法和多普勒超声检查估计主动脉根部的主动脉压力和血流。脉压最低和最高三分位数的受试者中，逆向波相对于正向波的形态相似。使用正性肌力药、血管升压药和血管扩张药（多巴酚丁胺、去甲肾上腺素和酚妥拉明）时也观察到类似结果，逆向波与正向波保持恒定比例。然而，硝酸甘油是一种对扩张肌性传导动脉有特定作用的药物，它使逆向波相对于正向波的幅度从基线时的0.26±0.018降至静脉注射硝酸甘油30 μg/min时的0.19±0.019（P<0.01）。这些结果最好用来自外周血管系统的正向波反射量大致恒定来解释。反射量可通过外周肌性传导动脉的扩张来改变，但对高血压时脉压升高的贡献不大。
