大鼠心率变异性频谱中高频成分的中枢机理分析

本文探讨心率变异性（ＨＲＶ）频谱中高频成分的中枢机理。对正常ＳＤ大量给予不同频率的人工通气并电刺激延髓疑核,观察ＨＲＶ频谱的改变,记录与呼吸节律同步的延髓头端腹外侧区（ｒＶＬＭ）及其周围区神经元细胞外单位放电,对ＨＲＶ和放电变异性进行相干函数分析。结果显示：（１）ＨＲＶ的高频成分的中心频率随着人工通气频率的增加而增加,呈高度线性相关,（ｒ＝０．８３,Ｐ〈０．０００１）;（２）对ｒＶＬＭ及其周围区与

The central mechanism of the high frequency component in heart rate variability in rat

Experiments were performed on 15 Sprague-Dawley rats to detect the effect of artificial ventilation of different frequencies on the high frequency component of heart rate variability (HRV) by autoregressive modeling with Burg algorithm. With continuous or intermittent electrical stimulation, different patterns of regulating activity of nucleus ambiguus in medulla on HRV were observed. Fast Fourier transform was used to analyze the coherence between neuronal discharge with respiratory rhythm in rostral ventrolateral medulla (rVLM) and HRV. The results showed that (1) the central frequency of high frequency (HF) component of HRV were moved closely with frequencies of artificial ventilation, (r = 0.83, P < 0.0001); (2) there was a favorable coherence between neuronal discharge with respiratory rhythm in rVLM and HRV in HF on spectrum, (k2 = 0.854 +/- 0.1); (3) the area of HF component in HRV was increased significantly during intermittent electrical stimulation of nucleus ambiguus in medulla. The central frequency of HF component in HRV was influenced mainly by frequencies of respiration. These results indicate a significant correlation between the HF in HRV and neuronal discharge with respiratory rhythm in rVLM, suggesting that rVLM participates in the regulation of HRV. The HF component of HRV may reflect mainly the fluctuating activity of vagal center. Coherence analysis of two signals provides a new method to confirm the type and interaction of neurons in the central cardiovascular system.