Heart rate behavior in children with atrial septal defect

The aim of this study was to assess heart rate variability, a noninvasive p arameter for studying the neurohumoral control of heart rate, in children w ith atrial septal defect. We examined five time-domain and three frequency- domain indices of heart rate variability determined from 24-hour Holter rec ordings in 20 children, aged 3-14 years, with secundum atrial septal defect who were about to undergo operation. The measures were compared to normal ranges and to the hemodynamic data of the preoperative cardiac catheterizat ion. Most indices of heart rate variability were moderately depressed in ch ildren with atrial septal defect. Our data revealed negative correlations b etween indices and the mean right atrial pressure and the enddiastolic righ t ventricular pressure, respectively. The study demonstrates the importance of the right ventricular filling pressures for the autonomic control of th e heart in children with atrial septal defect.