Autonomic regulation in fetuses with congenital heart disease

Background: Exposure to antenatal stressors affects autonomic regulation in fetuses. Whether the presence of congenital heart disease (CHD) alters the developmental trajectory of autonomic regulation is not known. Aims/Study Design: This prospective observational cohort study aimed to further characterize autonomic regulation in fetuses with CHD; specifically hypoplastic left heart syndrome (HLHS), transposition of the great arteries (TGA), and tetralogy of Fallot (TOF). Subjects: From 11/2010 to 11/2012,92 fetuses were enrolled: 41 controls and 51 with CHD consisting of 19 with HLHS, 12 with TGA, and 20 with TOF. Maternal abdominal fetal electrocardiogram (ECG) recordings were obtained at 3 gestational ages: 19-27 weeks (F1), 28-33 weeks (F2), and 34-38 weeks (F3). Outcome measures: Fetal ECG was analyzed for mean heart rate along with 3 measures of autonomic variability of the fetal heart rate: interquartile range, standard deviation, and root mean square of the standard deviation of the heart rate (RMSSD), a measure of parasympathetic activity. Results: During Fl and F2 periods, HLHS fetuses demonstrated significantly lower mean HR than controls (p < 0.05). Heart rate variability at F3, as measured by standard deviation, interquartile range, and RMSSD was lower in HLHS than controls (p < 0.05). Other CHD subgroups showed a similar, though nonsignificant trend towards lower variability. Conclusions: Autonomic regulation in CHD fetuses differs from controls, with HLHS fetuses most markedly affected. (C) 2015 Elsevier Ireland Ltd. All rights reserved.