Andriessen Peter, Koolen Andre M P, Berendsen Ralph C M, Wijn Pieter F F, ten Broeke Edith D M, Oei S Guid, Blanco Carlos E
Neonatal Intensive Care Unit, Máxima Medical Center, Veldhoven, The Netherlands.
Pediatr Res. 2003 Jan;53(1):89-97. doi: 10.1203/00006450-200301000-00016.
To examine the baroreceptor reflex function, a beat-to-beat analysis between systolic blood pressure (SBP) and R-R interval fluctuations was studied in 10 stable appropriate-for-gestational age preterm infants (range, 27.2-33.7 wk) in the first postnatal week during quiet sleep. Spectral power analysis, using fast Fourier transform, and transfer functions (gain and phase difference) between SBP and R-R fluctuations were estimated in a low-frequency band (LF, 0.03-0.2 Hz) and high-frequency band (HF defined as the frequency band between the 10th and 90th centiles of the individual respiratory frequency). The LF/HF ratio reflects the sympathovagal balance. The mean frequency (+/-SD) of LF peaks was centered at 0.07 +/- 0.02 Hz. The mean frequency (+/-SD) of the individual HF band was 0.82 +/- 0.21 Hz. The LF/HF ratio in the R-R interval series [median, 29; interquartile range (IQR), 16-40] was higher than in the SBP series (median, 8; IQR, 4-14). The gain between R-R interval and SBP fluctuations (median, 4.2 ms/mm Hg; IQR, 2.4-5.0) in the LF band was higher than in the HF band (median, 1.7 ms/mm Hg; IQR, 1.4-3.0). SBP fluctuations lead R-R interval fluctuations in the LF band with a median phase difference of +96 degrees (IQR, 67-132). At LF the fluctuations in SBP precede changes in R-R interval with a time delay of 3.8 s. These observations indicate a dominant role of the sympathetic system in stable preterm infants in comparison with published adult values. Cross-spectral analysis allows a test for tracking the development of the sympathetic system in neonates.
为了研究压力感受器反射功能，在出生后第一周安静睡眠期间，对10名胎龄合适的稳定早产儿（孕周范围为27.2 - 33.7周）的收缩压（SBP）和R-R间期波动进行逐搏分析。使用快速傅里叶变换进行频谱功率分析，并估计SBP与R-R波动之间在低频带（LF，0.03 - 0.2 Hz）和高频带（HF，定义为个体呼吸频率第10至90百分位数之间的频带）的传递函数（增益和相位差）。LF/HF比值反映交感神经-迷走神经平衡。LF峰值的平均频率（±标准差）集中在0.07±0.02 Hz。个体HF带的平均频率（±标准差）为0.82±0.21 Hz。R-R间期系列中的LF/HF比值[中位数为29；四分位间距（IQR）为16 - 40]高于SBP系列（中位数为8；IQR为4 - 14）。LF带中R-R间期与SBP波动之间的增益（中位数为4.2 ms/mm Hg；IQR为2.4 - 5.0）高于HF带（中位数为1.7 ms/mm Hg；IQR为1.4 - 3.0）。在LF带中，SBP波动领先于R-R间期波动，中位数相位差为 +96度（IQR为67 - 132）。在LF时，SBP波动比R-R间期变化提前3.8秒。这些观察结果表明，与已发表的成人值相比，交感神经系统在稳定的早产儿中起主导作用。交叉谱分析有助于检测新生儿交感神经系统的发育情况。
