SPECTRAL ANALYSIS OF HEART RATE AND RESPIRATORY PATTERNS IN INFANTS WITH APNEA.

The possibility that abnormal cardiorespiratory control might alter the frequency spectrum of heart rate and respiratory pattern led to the study of eleven infants admitted to hospital with apnea. Comparisons were made with twenty-three normal infants. Power spectra were computed for heart rate and respiratory patterns during quiet sleep for analysis of peaks at the respiratory frequency (HF, 0. 35-1 Hz) and at low frequency (LF, 0. 03-0. 15 Hz). No significant difference was found in HF or LF amplitude or frequency for either heart rate or respiratory patterns between infant apnea and control groups. Thus spectral analysis did not indicate abnormal autonomic control of heart and respiratory activity in infants with apnea.