超声对血管内皮功能血管扩张达峰时间的研究

Investigation on the peak time of endothelium-dependent dilatation by ultrasound

目的应用彩色多普勒超声连续多次测量反应性充血后的肱动脉内径值,并观察其达峰时间和连续测及峰值的次数,探讨反应性充血后血管内径测量的精确性。方法将30例高血压病、高脂血症、糖尿病(有其一即可)患者和30例正常人分为异常组和对照组,观察两组加压前和反应性充血后的肱动脉内径变化,以及反应性充血后肱动脉内径的达峰时间和连续测及峰值的次数。反应性充血后测量方法为:松袖套后20秒左右测量第一次,随后每间隔15秒测一次直到确定测值开始下降为止。结果异常组反应性充血后的肱动脉内径扩张百分率显著低于对照组(p<0.01),且低于正常值10%。异常组和对照组反应性充血后肱动脉内径达峰时间分别为67.33±11.32秒和64.07±12.36秒,连续测及峰值的次数分别为1.33±0.66次和1.30±0.53次,均无显著性差异(p>0.05)。结论肱动脉内径达峰时间存在个体差异,作者认为在松袖套后35秒开始,以不大于15秒为间隔,进行连续多次测量,并以50～80秒为重点观察时间段,能较准确地测到血管内径的最大值,从而使血管内皮功能的测量更精确。

Objective To observe the peak time and peak value of endothelium-dependent dilatation （EDD） after continuous measurement of internal diameter of brachial artery under reactive hyperemia by colour Doppler ultrasound in order to investigate the accuracy of this method. Methods In this experiment, 30 patients with hypertensive, hyperlipemia or diabetes （dysfunction group） and healthy subjects （control group） were enrolled. EDD and its peak time and peak value of the two groups were measured. The first measurement of brachial artery under reactive hyperemia was at about 20 sec after release and every 15 sec until the peak value dropped. Results Compared with control group, vasodilatation of brachial artery under reactive hyperemia was significantly lower in dysfunction group （ p〈 0.01）, which was 10% lower than normal value of EDD. The peak time under reactive hyperemia in dysfunction group and control group was 67.33 ± 11.32 and 64.07 ± 12.36 sec, and the frequency of peak value after continuous measurement was 1.33 ± 0.66 and 1.30 ± 0.53 times,respectively,which had no significant diference （ p 〉 0.05）. Conclusion There are individual differences in the peak time ofbrachial artery under reactive hyperemia. The first measurement is ideal at 35 sec after vasodilatation, continuously measured at no more than 15 sec as an interval and the observation period shall be focused at 50-80 sec, which makes the measurement of EDD more accurately.