自主神经在倾斜试验诱发血管迷走性晕厥中的作用

应用心率功率谱分析技术，评价倾斜试验诱发血管迷走性晕厥中自主神经的作用。结果显示，基础倾斜前基础阳性组高频（HF）成分明显低于静滴导两基肾上腺素倾斜试验阳性组（ISO阳性组）和对照组，低频（LF）／HF比值显著高于对照组。阳性反应前两个阳性组LF成分均较基础倾斜前显著增强（P＜0．05和＜0．01），HF成分则显著减弱（P均＜0．01），LF／HF比值亦显著增大（P均＜0．01）。表明自主神经功能调节障碍在倾斜试验诱发血管迷走性晕厥的发生机制中起着重要作用。

The Role of the Autonomic Nervous System in Vasovagal Syncope Induced by Multistage Isoproterenol Tilt Table Test

The role of the autonomic nervous system is studied in vasovagal syncope induced by multistage iso-proterenol tilt tab1e test (MITTT). The results showed that high-frequency (HF) components in basal positivegroup were significantly lower than those of MITTT positive group (ISO positive group) and control group. And1ow-frequency (LF)/HF ratio was significantly higher than those of the other groups be fore basa1 tilt test. Just be-fore the occurence of vasovaga1 syncope, the two positive groups had a significant increase in LF components, buta significant decrease in HF components, with a significant increase at LF/HF ratio. These results suggest that theimbalance of sympathetic and parasympathetic neural tones play an important role in the vasovagal syncope inducedduring MITTT. The LF/HF ratio is a practical measure which reflects the accuracy and sensibi1ity of interaction ofsympathetic and parasympathetic neural tones.