Signal‐averaged electrocardiographic late potentials in children with complete heart block

Abstract

Summary:The purpose of this study was to examine signalaveraged electrocardiographic (SA-ECG) late potentials to predict ventricular arrhythrmas during intrinsic cardiac rhythm and during ventricular pacing in children with complete heart block (CHB). Recordings of SA-ECG were obtained from eight patients (aged 3-18 years) with documented CHB. The etiology of CHB was congenital in four cases and acquired in four cases. Six of these patients underwent permanent pacemaker implantation. Comparisons of the SA-ECG were made before and during ventricular pacing. Abnormalities of SA-ECG during intrinsic cardiac rhythm were noted in four patients, all of whom were older than 14 years. Although there was no significant difference in SA-ECG parameters between patients with congenital CHB and acquired CHB, abnormal SA-ECG was noted in one of four patients with congenital CHB and in three of four patients with acquired CHB. Two patients without permanent pacemaker implantation had normal SA-ECG, but four of six patients with permanent pacemaker implantation had abnormal SA-ECG. Three of the four patients had abnormal SA-ECG during ventricular pacing, but the abnormal SA-ECG in one patient had normalized during ventricular pacing. It is important to record SA-ECG before and during ventricular pacing to detect late potentials in patients with CHB. It may be useful to record SA-ECG while changing the pacing site to h d ideal sites for electrode implantation for the potential prevention of ventricular arrhythmias.

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

“…To the best of our knowledge, only 3 reports exist relating to signal-averaged electrocardiographic parameters in normal children and infants. 10 " 12 Furthermore, again to our knowledge, no data have been published regarding QT dispersion as seen in the electrocardiograms of normal infants and children. The aim of the present study, therefore, was to evaluate age dependency of signal-averaged electrocardiographic parameters and QT dispersion in infants and children from birth to the age of 16 years.…”