Normal values of signal-averaged electrocardiographic parameters and QT dispersion in infants and children

Abstract

Ventricular late potentials, and dispersion of the QT interval, are markers for risk of ventricular arrhythmias. Normal values for these parameters are well established in adults, but may not apply for children. This study has investigated the age dependency of signal averaged electrocardiographic parameters and QT dispersion in 111 normal children aged from 5 days to 16 years. The results indicate that parameters change with age: duration of filtered QRS and low amplitude (< 40 /zV) terminal signal increase with age, especially in the younger patients. Filtered QRS is 88.9 ± 7.87 ms in infants, and increases to 108.7 ± 8.51 in teenagers (/><0.001). Low amplitude terminal signals are 17.0 ± 3.44 ms in infants, and 24.5 ± 5.64 ms in teenagers (p< 0.001). Root mean square of the last 40 ms decreases with age, but remains stable after the age of 10 years (122.4 ± 33-30 jiiV in infants, 60.9 ± 31.27 in teenagers,p<0.001). QT dispersion, on the other hand, does not change significantly with age. The mean value for the whole group is 36 ± 13.7 ms. A weak but significant correlation exists between QT dispersion and filtered QRS. Thus, age must be taken into consideration when interpreting signal-averaged electrocardiograms, but not when measuring QT dispersion.

QT Interval and Dispersion in Very Young Children Treated with Antipsychotic Drugs: A Retrospective Chart Review

“…The mean values of QTd and the rate-corrected QTd in our study are found to be comparable to those reported previously for normal control groups of children (Tutar et al, 1998;Vialle et al, 1999).…”

Effects of Cisapride on Ventricular Depolarization-Repolarization and Arrhythmia Markers in Infants

“…The 5 infants with a QTc 1450 ms after cisapride had a significant Biol Neonate 2001;80: [30][31][32][33][34] Zamora/Belli/Ferrazzini/Friedli Depolarization No significant differences were found for fQRS, LAS40, and RMS40 before and after cisapride (table 1). Using our reference normal values in infants, no ventricular late potentials were detected [24].…”

Does Low Birth Weight Affect P‐Wave and QT Dispersion in Childhood?

“…Anthropometric and clinical measurements are shown in [15][16][17][18][19][20][21][22][23][24][25][26][27][28] kg/m 2 vs 20.5 kg/m 2 , P = 0.415) were similar between the LBW group and the NBW group (Table I).…”

“…11,12 Corrected QT dispersion (QTc-d) has been accepted as a physiological variability of regional ventricular repolarization, and the QT-d value of >40 ms was identified as facilitating ventricular arrhythmias. 13 Although considerable evidence has been published on P-wave indices and QT derivatives and concerning autonomic imbalance of the heart, [14][15][16] no studies have been conducted on the effects of LBW on Pw-d and QTc-d, particularly in children. Since no data are available concerning Pw-d and QTc-d in children with LBW <2,500 g at birth who were born at term, we aim to compare Pw-d and QT-d between normal birth weight (NBW) and LBW children, as well as compare echocardiographic data such as left atrial and ventricular dimensions.…”