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

Abstract

To investigate autonomic regulation of neurocardiac signals in pediatric patients with cyclic vomiting syndrome (CVS). Fourteen patients with CVS, ages 3 to 16 years, were screened to eliminate any underlying cause for their symptoms, although 11 of the 14 patients had a history of migraine in the immediate family. Analysis of autonomic regulation was accomplished through power spectral analysis of the beat-to-beat heart rate variability signal. Data from affected patients were compared 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 computing a ratio of power in the low-frequency band (0. 02-0.15 Hz) to the power in the high-frequency band (0.15-0.4 Hz). Pediatric patients with CVS have an elevated sympathetic modulation of the sinus node as represented by the low frequency/high frequency ratio (1.45 +/- 0.42 in patients vs 0.89 +/- 0.29 in healthy control subjects, P <.001). The patients with CVS we studied have an autonomic imbalance with enhanced sympathetic and diminished parasympathetic vagal modulation of the heart.