Heart rate variability is depressed in the early transitional period for newborns with complex congenital heart disease

Mulkey SB, Govindan R, Metzler M, Swisher CB, Hitchings L, Wang Y, Baker R, Larry Maxwell G, Krishnan A, du Plessis AJ.
Clin Auton Res. 2020 Apr;30(2):165-172. doi: 10.1007/s10286-019-00616-w. Epub 2019 Jun 25.
PMID: 31240423
Similar articles
Select item 32003456



Purpose: To compare early changes in autonomic nervous system (ANS) tone between newborns with complex congenital heart disease (CHD) and newborns without CHD.

Methods: We performed a case-control study of heart rate variability (HRV) in newborns with complex CHD [transposition of the great arteries (TGA) or hypoplastic left heart syndrome (HLHS)] and low-risk control newborns without CHD. Cases with CHD were admitted following birth to a pediatric cardiac intensive care unit and had archived continuous ECG data. Control infants were prospectively enrolled at birth. ECG data in cases and controls were analyzed for HRV in the time and frequency domains at 24 h of age. We analyzed the following HRV metrics: alpha short (αs), alpha long (αL), root mean square short and long (RMSs and RMSL), low-frequency (LF) power, normalized LF (nLF), high-frequency (HF) power, and normalized HF (nHF). We used ANOVA to compare HRV metrics between groups and to control for medication exposures.

Results: HRV data from 57 infants with CHD (TGA, n = 33 and HLHS, n = 24) and from 29 controls were analyzed. The HRV metrics αS, RMSL, LF, and nLF were significantly lower in infants with CHD than in the controls. Due to the effect of normalization, nHF was higher in CHD infants (P < 0.0001), although absolute HF was lower (P = 0.0461). After adjusting for medications, αS and nLF remained lower and nHF higher in newborns with CHD (P < 0.0005).

Conclusions: Infants with complex CHD have depressed autonomic balance in the early postnatal period, which may complicate the fetal-neonatal transition.

Fig. 1 Sample detrended fluctuation analysis (DFA) plot for an infant with CHD and a control infant. Shown are DFA4 fluctuation functions obtained for 10 min of RRi of an infant in the control group and of an infant in the CHD group. The fluctuation functions are plotted as a function of the scale s in a log–log representation. ‘DFA4’ indicates that a fourth-order polynomial was used in the detrending process (refer to text for details). The short-term exponent (αS) was calculated from the scale region shown in the black dashed rectangle. The long-term exponent (αL) was calculated from the scale region shown in the blue dashed rectangle