Schechtman V L, Harper R K, Harper R M
Brain Research Institute, UCLA School of Medicine 90024-1761.
Pediatr Res. 1993 Nov;34(5):618-23. doi: 10.1203/00006450-199311000-00012.
Previous studies show alterations in the dynamic patterns of cardiac rate in several "at-risk" populations, including apparently healthy infants who subsequently die of the sudden infant death syndrome. In the present study, we examined the maturation of cardiac rate dynamics in normal infants during sleep-waking states over the first 6 mo of life. Instantaneous changes in cardiac R-R intervals were examined in 12-h recordings of 24 normal full-term infants; each infant was recorded at 1 wk and at 1, 2, 3, 4, and 6 mo of age. Scatter plots, consisting of each cardiac R-R interval plotted as a function of the previous interval (Poincaré plots), were constructed for each sleep-waking state in each recording. Analyses of variance were performed on the dispersion of intervals after long and short R-R intervals. In neonates, Poincaré plots showed significantly more next-interval dispersion after a long R-R interval than after a short interval, a pattern similar to those observed in older infants and in healthy adults. However, between 1 wk and 1 mo of age, this pattern disappeared and returned gradually beginning at 2 mo of age. The scatter of points in Poincaré plots of infants 1 mo of age approached the patterns of at-risk populations, including infants who subsequently died of the sudden infant death syndrome. These patterns at 1 mo may be indicative of increased vulnerability in normal infants after the neonatal period.
先前的研究表明，在包括随后死于婴儿猝死综合征的看似健康的婴儿在内的几个“高危”人群中，心率的动态模式存在改变。在本研究中，我们检查了正常婴儿在出生后头6个月的睡眠-清醒状态中心率动态的成熟情况。对24名正常足月婴儿进行了12小时的记录，检查了心脏R-R间期的瞬时变化；每个婴儿在1周龄以及1、2、3、4和6月龄时进行记录。针对每次记录中的每个睡眠-清醒状态，构建散点图，将每个心脏R-R间期作为前一个间期的函数进行绘制（庞加莱图）。对长R-R间期和短R-R间期后的间期离散度进行方差分析。在新生儿中，庞加莱图显示长R-R间期后的下一个间期离散度明显高于短间期后的离散度，这一模式与在较大婴儿和健康成年人中观察到的模式相似。然而，在1周龄至1月龄之间，这种模式消失，并在2月龄时开始逐渐恢复。1月龄婴儿的庞加莱图中的点分布接近高危人群的模式，包括随后死于婴儿猝死综合征的婴儿。1月龄时的这些模式可能表明新生儿期后正常婴儿的易感性增加。
