. Author manuscript; available in PMC: 2021 Apr 17.

Published in final edited form as: Pediatr Res. 2020 May 12:10.1038/s41390-020-0952-0. doi: 10.1038/s41390-020-0952-0

Table 2:

Correlation of Spectral and Time Domain Metrics of ANS Tone

	nLF	nHF	LF	HF	HR	Alpha 1	Alpha 2	RMS 1
nLF
nHF	−0.95^*
LF	0.37^*	−0.25^*
HF	−0.02	0.15^*	0.90^*
HR	−0.15^†	−0.03	−0.50^*	−0.52^*
Alpha 1	0.71^*	−0.63^*	0.77^*	0.49^*	−0.37^*
Alpha 2	−0.05	−0.05	−0.79^*	−0.80^*	0.44^*	−0.54^*
RMS 1	0.23^*	−0.11^‡	0.90^*	0.87^*	−0.58^*	0.61^*	−0.76^*
RMS 2	0.39^*	−0.29^*	0.91^*	0.82^*	−0.56^*	0.70^*	−0.62^*	0.94^*

^‡

P < 0.05

^†

P < 0.01

P < 0.001

Abbreviations: nLF = normalized low frequency; nHF = normalized high frequency; LF = low frequency; HF = high frequency; HR = mean heart rate; alpha 1= alpha short; alpha 2 = alpha long; RMS 1 = root mean square 1; RMS 2 = root mean square 2