【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。

    The role of autonomic nervous system in vasovagal syncope Luo Wei, Ren Ziwen, Ding Yansheng, et al. Department of Cardiology,First Affiliated Hospital, Beijing Medical University, Beijing 100034

    【Abstract】 Objective To study how theautonomic nervous system works in the vasovagal syncope.Me-thods Ninety-four patients with recurrent unexplained syncope underwenttilt table test. The analysis of the Holter-monitoring, blood pressure and the heart ratevariability of the patients were performed during tilt. The LF, HF and VLF of frequencydomain were studied for investigating the mechanism of vasovagal syncope. Results 44 among 94 patients had syncope. 32 got syncope during baselinetilt table test (BTTT), with the positive rate of 34.0% (32/94). 12 got syncope duringisoproterenol-tilt table test, with the positive rate of 12.8% (12/94). LF and HFdecreased significantly during syncope, meanwhile VLF significantly increased in all thepatients with syncope.Conclusion (1) During theperiod of vasovagal syncope, both sympathetic and vagal nerve tones were inhibited. (2)Theincrease of VLF was significantly correlated to the decrease of LF. The significance ofVLF increase remains to be observed.

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