Abstract:

Objective    To analyze the cerebral blood flow dynamics of vasovagal syncope（VVS） by transcranial cerebral Doppler（TCD） and explore the clinical value of TCD to VVS. Methods    A total of 38 children with vasovagal syncope and 20 healthy children received head-up tilt test（HUTT）. In the process of test，they were monitored by TCD. Results    Under basic condition，there were no obvious differences between patients and healthy children on the result of TCD. In the process of HUTT for healthy children，there were no obvious differences on the result of TCD. In the process of HUTT for vasovagal syncope children，compared with data of TCD under basic condition，the cerebral blood flow velocity（Vs，Vd，Vm） and pulse index（PI） had great improvement when syncope was induced by HUTT. Conclusion    Patients with vasovagal syncope have obstacles in terms of cerebral blood flow regulation. TCD can become a routine examination method in those children with vasovagal syncope.

Key words: vasovagal syncope, transcranial cerebral Doppler（TCD）, cerebral blood flow velocity, pulse index（PI）

摘要：

目的    采用经颅多普勒超声（TCD）分析血管迷走性晕厥（VVS）的脑血流动力学特点，并探讨TCD对VVS的临床应用价值。方法    对2011年12月至2013年8月于兰州大学第二医院小儿心血管科就诊的38例血管迷走性晕厥患儿，及20名体检健康儿童行直立倾斜试验，并应用TCD进行监测。结果    基础状态下，观察组与对照组比较，左右大脑中动脉的收缩期血流速度（Vs）、舒张末期血流速度（Vd）、平均血流速度（Vm）差异无统计学意义（P＞0.05），脉冲指数（PI）值差异无统计学意义（P＞0.05）；对照组行直立倾斜试验后与基础状态时比较，左右大脑中动脉的Vs、Vd、Vm差异无统计学意义（P＞0.05），PI值差异无统计学意义（P＞0.05）；观察组通过直立倾斜试验诱发血管迷走性晕厥阳性反应时与基础状态时比较，左右大脑中动脉的Vs、Vd、Vm明显加快（P＜0.05），PI值明显升高（P＜0.05）。结论    VVS发生时，脑血管阻力增加，脑血流调节障碍；TCD检查对于判断VVS患儿脑血流状态具有重要价值。

关键词: 血管迷走性晕厥, 经颅多普勒, 脑血流速度, 脉冲指数