Brown T E, Beightol L A, Koh J, Eckberg D L
Department of Medicine, Hunter Holmes McGuire Department of Veterans Affairs Medical Center, Richmond, Virginia 23249.
J Appl Physiol (1985). 1993 Nov;75(5):2310-7. doi: 10.1152/jappl.1993.75.5.2310.
Frequency-domain analyses of R-R intervals are used widely to estimate levels of autonomic neural traffic to the human heart. Because respiration modulates autonomic activity, we determined for nine healthy subjects the influence of breathing frequency and tidal volume on R-R interval power spectra (fast-Fourier transform method). We also surveyed published literature to determine current practices in this burgeoning field of scientific inquiry. Supine subjects breathed at rates of 6, 7.5, 10, 15, 17.1, 20, and 24 breaths/min and with nominal tidal volumes of 1,000 and 1,500 ml. R-R interval power at respiratory and low (0.06-0.14 Hz) frequencies declined significantly as breathing frequency increased. R-R interval power at respiratory frequencies was significantly greater at a tidal volume of 1,500 than 1,000 ml. Neither breathing frequency nor tidal volume influenced average R-R intervals significantly. Our review of studies reporting human R-R interval power spectra showed that 51% of the studies controlled respiratory rate, 11% controlled tidal volume, and 11% controlled both respiratory rate and tidal volume. The major implications of our analyses are that breathing parameters strongly influence low-frequency as well as respiratory frequency R-R interval power spectra and that this influence is largely ignored in published research.
R-R间期的频域分析被广泛用于估计人体心脏自主神经活动水平。由于呼吸会调节自主神经活动，我们针对9名健康受试者，确定了呼吸频率和潮气量对R-R间期功率谱的影响（快速傅里叶变换法）。我们还查阅了已发表的文献，以确定这一新兴科学研究领域的当前做法。仰卧位受试者分别以6、7.5、10、15、17.1、20和24次/分钟的呼吸频率，以及标称潮气量1000毫升和1500毫升进行呼吸。随着呼吸频率增加，呼吸频率和低频（0.06 - 0.14赫兹）下的R-R间期功率显著下降。潮气量为1500毫升时，呼吸频率下的R-R间期功率显著高于1000毫升时。呼吸频率和潮气量均未对平均R-R间期产生显著影响。我们对报告人体R-R间期功率谱的研究进行的综述表明，51%的研究控制了呼吸频率，11%控制了潮气量，11%同时控制了呼吸频率和潮气量。我们分析的主要意义在于，呼吸参数强烈影响低频以及呼吸频率下的R-R间期功率谱，而这一影响在已发表的研究中大多被忽视。
