Electrocardiographic Pattern of Apparently Healthy Primary School Children Aged 5-15 Years, in Kano

Abstract

Background: Electrocardiography (ECG) is a simple, noninvasive, and relatively cheap investigative tool used for cardiac evaluation. However, there are limited electrocardiographic studies of Nigerian children. Adult studies of ECG have shown significant differences between Black and Caucasian populations. These differences may also be seen in children, hence, the need to develop local reference values. Materials and Methods: This was a cross-sectional study and multistage random sampling method was applied to select 650 subjects. The ECG machine was a portable heated stylus direct writing AT-2 Swiss made electrocardiograph (Schiller AG Cardiovit CH6341). Results: There were 350 males (53.3%) and 300 females (46.7 %), with a male:female ratio of 1.2:1. The mean heart rate decreased with increasing age. R-wave amplitudes were higher in the left precordial leads, in keeping with left ventricular dominance. Mean values were higher in boys than girls in the three age-groups in most of the precordial and limb leads. In V 4 R, V 2 , and V 3 highest mean R wave voltages of 0.5 ± 0.1, 1.4 ± 0.3, and 1.4 ± 0.2 mV, respectively, were recorded in the 5-7-year-old. While in V 5 and V 6 , the mean R waves were higher in the 12-15-year-old age group (3.7± 0.5 and 2.5±0.4 mV, respectively). The S-waves showed progressive decrease in its amplitude on the left precordial leads with increasing age. Conclusion: The mean values in heart rate, QRS duration, PR interval, and P-wave amplitude showed higher amplitudes in boys. Similarly higher amplitudes of R-waves in boys were recorded in precordial leads V 2 , V 3 , V 5 , and V 6 in the three age groups.