心率功率谱分析影响呼吸性窦性心律不齐的因素

用大鼠心电R波峰触发心率计,心率信号经电子计算机采样后进行快速富里叶(FFT)变换,得出心率变异的功率谱分布。以心率功率谱中高频峰密度作为呼吸性窦性心律不齐的客观指标,定量观察了肌松、断双侧迷走神经、开胸及不同人工呼吸频率对大鼠呼吸性窦性心律不齐的影响。结果表明迷走神经活动引起的呼吸性窦性心律不齐占整个呼吸性窦性心律不齐的72%,因此心率功率谱分析有可能成为无创检测心迷走神经功能状态的方法。

APPLICATION AND SIGNIFICANCE OF HEART RATE POWER SPECTRAL ANALYSIS IN RESPIRATORY SINUS ARRHYTHMIA(RSA)IN RATS

The beat-to-beat variations of R-R interval were obtainedfrom ECG in 30 anesthetized rats of either sex weighing 280-320g.Thepeak of R waves triggered a heart rate tachometer and the signals werefed to an APPLE-II microcomputer(the sampling rate was 10Hz and512 points were used)for fast fourier analysis with power spectral(PS)program.The PS of heart rate variability was obtained and the powerspectral densities were calculated.The power spectral density of highfrequency peak in heart rats PS is a sensitive quantitative criterion forRSA.Experiment procedures including muscle relaxant,bilateral vagoto-my,thoracotomy,frequency changes of artificial respiration were doneto see the effects on RSA detected by high frquency peak density(HFPD)in the PS.The results showed that the HFPD was contributed by mecha-nical,central and reflexogenic factors,the latter two were caused byvagus contributing about 72% of the HFPD.Thus heart rate PS analysiscould be a criterion for noninvasive quantitative test of parasympatheticactivity.