【摘要】 目的探索自主神经系统如何介导血管迷走性晕厥的发生。方法对９４例不明原因晕厥的病人进行了倾斜试验。倾斜过程中动态监测心电图、血压和心率。进行心率变异性分析。结果４４例发生晕厥，其中基础倾斜试验晕厥３２例，阳性率３４．０％；异丙肾上腺素晕厥１２例，阳性率增加１２．８％。晕厥时ＬＦ及ＨＦ明显下降，ＶＬＦ明显升高。结论（１）血管迷走性晕厥时，交感神经和迷走神经张力受抑制，导致血管扩张，血压下降。（２）ＶＬＦ的升高与ＬＦ的下降明显相关。ＶＬＦ升高的意义有待深入研究更多还原

【Abstract】 Objective To study how the autonomic nervous system works in the vasovagal syncope.Methods Ninety-four patients with recurrent unexplained syncope underwent tilt table test. The analysis of the Holtermonitoring, blood pressure and the heart rate variability of the patients were performed during tilt. The LF, HF and VLF of frequency domain were studied for investigating the mechanism of vasovagal syncope. Results 44 among 94 patients had syncope. 32 got syncope during baseline tilt table test (BTTT), with the positive rate of 34.0% (32/94). 12 got syncope during isoproterenoltilt table test, with the positive rate of 12.8% (12/94). LF and HF decreased significantly during syncope, meanwhile VLF significantly increased in all the patients with syncope.Conclusion (1) During the period of vasovagal syncope, both sympathetic and vagal nerve tones were inhibited. (2)The increase of VLF was significantly correlated to the decrease of LF. The significance of VLF increase remains to be observed.更多还原