Evaluation of neurocardiac signals in pediatric patients with cyclic vomiting syndrome through power spectral analysis of heart rate variability

Objective: To investigate autonomic regulation of neurocardiac signals in p ediatric patients with cyclic vomiting syndrome (CVS). Methods: Fourteen patients with CVS, ages 3 to 16 years, were screened to e liminate any underlying cause for their symptoms, although 11 of the 14 pat ients had a history of migraine in the immediate family Analysis of autonom ic regulation was accomplished through power spectral analysis of the beat- to-beat heart rate variability signal. Data from affected patients were com pared with data from 38 control subjects, ages 5 to 16 years, by a one-way analysis of variance. A measure of sympathovagal balance was obtained by co mputing a ratio of power in the low-frequency band (0.02-0.15 Hz) to the po wer in the high-frequency band (0.15-0.4 Hz). Results: pediatric patients with CVS have an elevated sympathetic modulatio n of the sinus node as represented by the low frequency/high frequency rati o (1.45 +/- 0.42 in patients vs 0.89 +/- 0.29 in healthy control subjects, P < .001). Conclusions: The patients with CVS we studied have an autonomic imbalance w ith enhanced sympathetic and diminished parasympathetic vagal modulation of the heart.