ABSTRACT
Pediatric mortality represents a major problem all over the world. During infancy, arrhythmia may be an important factor in the pathogenesis of some of these life-threate ling events. Congenital heart diseases increase the liability for many cardiac arrhythmias. Ventricular late potentials have shown to be markers for risk of ventricular arrhythmias. There is only limited data on normal reference values for signal- averaged electrocardiogram [SFECG] in pediatric population. In this sturdy, we tried to establish ranges for SAECG parameters in normal children and in patients with congenital cardiac defects. One hundred and fifty infant's and children were the study population. Fifty [50] children had congenital a cyanotic heart disease, 29 were males with a mean age +/- SD of 18.75 +/- 13.9 months and 50 children had congenital cyanotic heart diseases, 18 were males with a mean age of 5.62 +/- 3.0 months. 50 age- and sex- matched healthy individuals were served as controls. The SAECG parameters include QRS duration in milliseconds [msec], Root Mean Square voltage [RMS] in microvolts [micro v], Root Mean Square of the last 40 millisecond of the QRS comply [RMS 40] in micro V and the duration of low amplitude signal [< 40 micro V] at the terminal QRS [LAS] in msec. The results showed that, in normal subjects, the QRS duration ranged iron 80.5 to 100.5 msec, RMS voltage ranged from 158.6 to 240.0 micro V, RMS-4O voltage ranged from 44.5 to 126.1 micro V and the duration of LAS ranged from 2.7 to 10.3 msec. In acyanotics, the mean +/- SD for QRS duration was 101.2 +/- 85.2 msec, for RMS was 197.9 +/- 92.7 micro V, for RMS-40 was +/- 79.9 + 118.0 micro V and for LAS was 10.5 +/- 7.4 msec. In cyanotic, QRS duration was 127. +/- 11.8 msec, RMS was 128.5 +/- 60.1 micro V, RMS-40 was 35.34 + 2.4 micro V and LAS was 22.8 + 2.3 msec. Cyanotic patients had a significantly wide QRSD 8 LAS and significantly low RMS and RMS-40 than a cyanotic [p > 0.05]
Conclusion: our result; provide a basis for interpretation of SAECG in Children. Normal ranges for the various parameters were determined. In cyanotic, the late potentia3 are markedly abnormal in comparison to the little change in cyanotic rendering patients with cyanotic heart defects are highly susceptible for arrhythmia and arrhythmia-induced complications