Silva Carla Cristiane, Bertollo Maurizio, Reichert Felipe Fossati, Boullosa Daniel Alexandre, Nakamura Fábio Yuzo
1 State University of Northern Paraná.
2 University of Chieti.
Pediatr Exerc Sci. 2017 May;29(2):228-236. doi: 10.1123/pes.2016-0085. Epub 2016 Sep 6.
To examine which body position and indices present better reliability of heart rate variability (HRV) measures in children and to compare the HRV analyzed in different body positions between sexes.
Twenty eutrophic prepubertal children of each sex participated in the study. The RR intervals were recorded using a portable heart rate monitor twice a day for 7 min in the supine, sitting, and standing positions. The reproducibility was analyzed using the intraclass correlation coefficient (ICC; two way mixed) and within-subject coefficient of variation (CV).Two-way ANOVA with repeated measures was used to compare the sexes.
High levels of reproducibility were indicated by higher ICC in the root-mean-square difference of successive normal RR intervals (RMSSD: 0.93 and 0.94) and Poincaré plot of the short-term RR interval variability (SD1: 0.92 and 0.94) parameters for boys and girls, respectively, in the supine position. The ICCs were lower in the sitting and standing positions for all HRV indices. In addition, the girls presented significantly higher values than the boys for SDNN and absolute high frequency (HF; p < .05) in the supine position.
The supine position is the most reproducible for the HRV indices in both sexes, especially the vagal related indices.
研究在儿童中哪种体位和指标能使心率变异性（HRV）测量具有更高的可靠性，并比较不同体位下男女之间的HRV分析结果。
每种性别各20名营养良好的青春期前儿童参与了该研究。使用便携式心率监测仪，每天两次，每次7分钟，记录仰卧位、坐位和站立位的RR间期。使用组内相关系数（ICC；双向混合）和受试者内变异系数（CV）分析再现性。采用重复测量的双向方差分析比较性别差异。
仰卧位时，男孩和女孩连续正常RR间期的均方根差（RMSSD：分别为0.93和0.94）和短期RR间期变异性的庞加莱图（SD1：分别为0.92和0.94）参数的ICC较高，表明具有较高的再现性。所有HRV指标在坐位和站立位时的ICC较低。此外，仰卧位时女孩的总体标准差（SDNN）和绝对高频（HF）值显著高于男孩（p < 0.05）。
仰卧位对男女的HRV指标来说都是最具再现性的，尤其是与迷走神经相关的指标。
