Electrocardiograms in school-aged healthy Polish children - an observational study.

Background: Electrocardiographic (ECG) examination has long been used to assess cardiovascular function in clinical practice. Age-related ECG changes are observed as the cardiovascular system matures from the neonatal period to adolescence.

Aim: This study aimed to evaluate effects of sex and age on ECG parameters in healthy schoolchildren.

Methods: The study included 336 healthy participants aged 5-12 years from the Masovian voivodeship. Children were divided into age groups of 5-8 and 9-12 years. Values for heart rate (HR), time intervals and amplitudes of P and QRS waves, and QRS axis for pediatric ECGs were estimated.

Results: Significant differences between boys and girls aged 5-8 years old were discovered for such parameters as PR interval, R-wave, S-wave, and the R/S ratio. Age-related decline in HR, Q-wave in V5 and V6, R-wave in V1-V4, and increase in QRS duration were noted. Girls presented a higher HR and shorter QRS than boys. HR, QRS axis, P wave amplitude in lead II, and amplitude of R and S in the precordial leads were different in our population than those previously reported.

Conclusions: Pediatric ECG tracings were estimated for the first time for healthy Polish schoolchildren. Sex-related differences in selected ECG parameters in the younger age group were noticed. Several parameters differed from those previously reported in other ethnic populations. These findings are clinically significant and suggest that diagnostic criteria for pediatric ECG should be revised to establish if they are justifiable for the entire population.