Costa O, Freitas J, Puig J, Carvalho M J, Freitas A, Ramos J, Puga N, Lomba I, Fernandes P, de Freitas F
Servico de Terapêutica Médica da F. M. do Porto.
Rev Port Cardiol. 1991 Jan;10(1):23-8.
Characterize power spectrum pattern of the heart rate variability and assessment of the relative contributions of sympathetic and parasympathetic cardiac nervous system control in athletes.
Prospective study of athletes and sedentary healthy control group sex and age matched.
8 athletes, 3 female and 5 male, swimming (4), canoeing (2) and cycling (2), aged 17.4 +/- 3.6 years, and 8 sedentary healthy controls. ECG signals were recorded after a period of 15 minutes in supine rest with controlled breathing at 15 cycles/min. Signal acquisition was done at 300 samples/sec. From 512 consecutive heart beats, we calculated the average, the standard deviation, the maximum and the minimum values and the rate between the longest and the shortest R-R interval (E/I). We also calculated, after computing the fast Fourier transform, the total spectrum power, the low frequency component (LF, from 0.01 to 0.15 Hz) and the high frequency component (HF, greater than 0.15 Hz) and its ratio (LF/HF).
The average R-R interval was 921 +/- 154.2 msecs and 673.2 +/- 98 msecs, the standard deviation was 72.5 and 29.4 msecs and the ratio E/I 1.63 +/- 0.14 and 1.28 +/- 0.08, respectively for athletes and control group. Differences between groups were significant (p less than 0.01) for all parameters, with higher variability in the athletes. Both spectral bands (LF and HF) and higher power in athletes (LF = 0.54 +/- 0.23 and HF = 0.76 +/- 0.14) than in the control group (LF = 0.14 +/- 0.10 and HF = 0.18 +/- 0.15) (p less than 0.001). There were no significant differences for LF/HF ratio, or normalized LF (LF%) or normalized HF (HF%) between groups.
The present results indicates higher power of both spectral bands (LF and HF) and higher amplitude of the respective peaks in athletes when compared with healthy sedentary, with a clear predominance of the HF band in the total spectral power density, which suggest that the higher heart rate variability observed in athletes reveals the predominance of parasympathetic activity, without reduction of the sympathetic tone.
描述运动员心率变异性的功率谱模式，并评估交感和副交感心脏神经系统控制的相对贡献。
对年龄和性别匹配的运动员和久坐不动的健康对照组进行前瞻性研究。
8名运动员，3名女性和5名男性，分别从事游泳（4人）、皮划艇（2人）和自行车运动（2人），年龄17.4±3.6岁，以及8名久坐不动的健康对照者。在仰卧休息15分钟后，以每分钟15次的控制呼吸记录心电图信号。信号采集频率为每秒300个样本。从连续512次次心跳中，我们计算了平均值、标准差、最大值和最小值以及最长与最短R-R间期之比（E/I）。在计算快速傅里叶变换后，我们还计算了总频谱功率、低频成分（LF，0.01至0.15赫兹）和高频成分（HF，大于0.15赫兹）及其比值（LF/HF）。
运动员组和对照组的平均R-R间期分别为921±154.2毫秒和673.2±98毫秒，标准差分别为72.5和29.4毫秒，E/I比值分别为1.63±0.14和1.28±0.08。所有参数在两组之间均有显著差异（p<0.01），运动员的变异性更高。运动员的两个频谱波段（LF和HF）以及功率均高于对照组（LF = 0.54±0.23，HF = 0.76±0.14）（对照组LF = 0.14±0.10，HF = 0.18±0.15）（p<0.001）。两组之间的LF/HF比值、归一化LF（LF%）或归一化HF（HF%）无显著差异。
目前的结果表明，与久坐不动的健康人相比，运动员的两个频谱波段（LF和HF）功率更高，各自峰值的幅度更大，在总频谱功率密度中HF波段明显占主导，这表明运动员中观察到的较高心率变异性揭示了副交感神经活动占主导，而交感神经张力并未降低。
