Section of Anesthesiology, Department of Surgery, University of Pisa, Pisa, Italy.
J Hypertens. 2012 Aug;30(8):1614-9. doi: 10.1097/HJH.0b013e328354dd44.
A direct measurement of carotid stiffness implies an accurate assessment of changes in carotid diameter and pressure during cardiac cycle. Radiofrequency-based wall-tracking systems (WTS) are capable to track arterial wall movement with adequate spatial and temporal resolution, and to provide carotid pressure estimate from calibrated distension waveforms. The aim of the present study was to compare the values of carotid distension and beta-stiffness index acquired in the same population by two commercially available WTS, in order to determine whether their measures can be pooled in clinical studies. In addition, a local carotid pulse pressure (PP) obtained from calibrated distension waveforms was compared with that obtained from pressure waveforms.
In 105 patients, right common carotid artery (CCA) systo-diastolic excursions were assessed during the same session and by the same operator both by WTS implemented in Esaote system (QAS, MyLab) and in Aloka system (E-track; Alpha 10). In 78 patients, carotid PP was also estimated by applanation tonometry.
Despite comparable blood pressure and heart rate values during the two acquisitions, CCA distension was significantly lower (363 ± 162 vs. 458 ± 176 μm, P < 0.0001) and beta-stiffness index (11.9 ± 5.5 vs. 9.4 ± 3.8, P < 0.0001) higher with Esaote as compared to Aloka. PP obtained from calibrated pressure and distension waveforms was comparable (42.6 ± 11.4 vs. 43.0 ± 10.7 mmHg, P = 0.51).
The values of carotid distension and stiffness obtained by two different WTS are not interchangeable and cannot be merged into a common database. Calibrated distension curves may provide an acceptable estimate of local carotid pressure.
直接测量颈动脉僵硬度意味着能够准确评估心动周期中颈动脉直径和压力的变化。基于射频的壁跟踪系统（WTS）能够以足够的空间和时间分辨率跟踪动脉壁运动，并从校准的膨胀波中提供颈动脉压力估计。本研究的目的是比较两种商业上可用的 WTS 在同一人群中获得的颈动脉膨胀和β-僵硬度指数值，以确定它们的测量值是否可以在临床研究中合并。此外，还比较了从校准膨胀波中获得的局部颈动脉脉搏压（PP）与从压力波中获得的脉搏压。
在 105 例患者中，由同一操作人员在同一时间段内使用 Esaote 系统（QAS，MyLab）和 Aloka 系统（E-track；Alpha 10）中的 WTS 评估右颈总动脉（CCA）的收缩-舒张运动。在 78 例患者中，还通过平板压力测量法估计颈动脉 PP。
尽管两次采集时的血压和心率值相似，但与 Aloka 相比，Esaote 获得的 CCA 膨胀明显更低（363±162 对 458±176μm，P<0.0001），β-僵硬度指数更高（11.9±5.5 对 9.4±3.8，P<0.0001）。从校准压力和膨胀波获得的 PP 是可比的（42.6±11.4 对 43.0±10.7mmHg，P=0.51）。
两种不同 WTS 获得的颈动脉膨胀和僵硬度值不可互换，不能合并到一个共同的数据库中。校准的膨胀曲线可以提供局部颈动脉压力的可接受估计。
