迷走神经兴奋性对HRV的影响及其机制的初步分析

实验在氯醛糖加氨基甲酸乙酯麻醉的新西兰兔上进行。记录血压，心率，心电图和心率变异性频谱分析。电刺激减压神经，疑核和右侧迷走神经外周端，均引起心率和血压下降，总变异性，低频成分，高频成分，ＬＦ／ＨＦ比值和极代频成分增大。静脉注射阿托品可使上述反应显著减小，而静脉注射心得安仅可阻断ＤＮ和ＮＡ所致ＬＦ的增大。

Effect of vagi excitation on HRV and the exploration of its mechanism]

The experiments were performed on rabbits anaesthetized with urethane and chloralose. The ECG heart rate and blood pressure were recorded. The power spectrum analysis of R-R interval (RRI) was done by computer. Electrical stimulation of nucleus ambiguus (NA), depressor nerve (DN) and the peripheral end of right vagus (RV) all evoked a decrease in heart rate and blood pressure (P < 0.001), and an increase in LF, HF, LF/HF, TV and VLF (P < 0.05-0.001); The LF, HF, LF/HF, TV and VLF were significantly decreased (P < 0.05-0.01) by pretreatment with intravenous injection of atropine. The enhancement of LF during stimulating DN and NA were attenuated (P < 0.05) by prior intravenous injection of propranolol. It is suggested that vagus activity is one of the major regulator of HRV and mediates VLF. The HF is mediated only by vagi, while the LF is mediated by both vagi and sympathetic system.