Ting C T, Chang M S, Wang S P, Chiang B N, Yin F C
Department of Medicine, Veterans General Hospital, Taichung, Taiwan, ROC.
Cardiovasc Res. 1990 Nov;24(11):865-72. doi: 10.1093/cvr/24.11.865.
The aim was to compare regional wave transmission and reflection properties along the aorta in age matched normotensive and hypertensive subjects.
Simultaneous upstream and downstream micromanometer pressures were recorded at five regions from the ascending aorta to the iliac artery. Recordings were made in the baseline condition in both groups and during sustained isometric handgrip exercise in the normotensives to see if increasing the blood pressure to hypertensive levels would eliminate baseline differences between the two groups.
Only subjects who had no coronary or valvular heart disease were studied. Normotensive subjects (n = 8) were selected from those undergoing electrophysiological testing whose blood pressures were consistently in the normal range (systolic less than 140, diastolic less than 90 mm Hg). Age matched hypertensive subjects (n = 17) were those in whom secondary causes of hypertension were excluded and who had repeated measurements of raised blood pressure.
In each region pulse wave velocity was estimated from the simultaneous upstream and downstream pressure records using the foot to foot method, and apparent phase velocity was obtained from Fourier analysis of the two pressures. The intensity of wave reflections was judged by the magnitude of fluctuations of the harmonics of apparent phase velocity about the mean of the higher frequency harmonics. In both groups in the baseline state there were regional variations in the pulse wave velocity with the lowest values occurring just proximal to the renal arteries and highest values occurring in the iliac artery. Likewise, in both groups the extent of wave reflections varied regionally--pronounced reflections were seen in the ascending aorta and from just proximal to the renal arteries to the aortic bifurcation but not in the mid-thoracic or iliac regions. The hypertensives had higher pulse wave velocity than normotensives only in the iliac artery (780 v 567 cm.s-1) and had more reflections in the three regions in which reflections were evident. Although handgrip in the normotensive group eliminated regional differences in pulse wave velocity between the groups, reflections were still greater in the hypertensives.
Essential hypertension affects the regional properties of the aortic wall. These alterations are manifested by increased peripheral wave-speed and increased wave reflections along the aorta. The differences in wavespeed but not reflection properties are eliminated when the pressures are matched by handgrip, suggesting that factors other than the level of blood pressure per se are responsible for the alterations in reflection properties.
旨在比较年龄匹配的正常血压者和高血压患者主动脉各节段的波传导和反射特性。
在从升主动脉至髂动脉的五个节段同时记录上游和下游微测压压力。两组均在基础状态下进行记录，正常血压者在持续等长握力运动期间也进行记录，以观察将血压升高至高血压水平是否会消除两组之间的基础差异。
仅研究无冠心病或瓣膜性心脏病的受试者。正常血压者（n = 8）选自接受电生理检查且血压始终在正常范围内（收缩压低于140，舒张压低于90 mmHg）的人群。年龄匹配的高血压患者（n = 17）为排除高血压继发原因且多次测量血压升高者。
在每个节段，使用足对足法根据同时记录的上游和下游压力估算脉搏波速度，并通过对两种压力进行傅里叶分析获得视相速度。通过视相速度谐波围绕高频谐波平均值的波动幅度判断波反射强度。在基础状态下，两组的脉搏波速度均存在节段性差异，最低值出现在肾动脉近端，最高值出现在髂动脉。同样，两组的波反射程度也存在节段性差异——在升主动脉以及肾动脉近端至主动脉分叉处可见明显反射，而在胸段中部或髂动脉节段未见反射。高血压患者仅在髂动脉处的脉搏波速度高于正常血压者（780对567 cm·s-1）且在三个可见反射的节段反射更多。尽管正常血压组的握力运动消除了两组之间脉搏波速度的节段性差异，但高血压患者的反射仍更大。
原发性高血压影响主动脉壁的节段特性。这些改变表现为外周波速增加以及沿主动脉的波反射增加。当通过握力使血压匹配时，波速差异消除，但反射特性差异未消除，这表明除血压水平本身外，其他因素也导致了反射特性的改变。
