There are few studies for detecting rhythm abnormalities among healthy children and adolescents. The aim of the study was to investigate the prevalence of abnormal electrocardiographic findings in the young Iranian population and its association with blood pressure and obesity.

A total of 15084 children and adolescents were examined in a randomly selected population of Tehran city, Iran, between October 2017 and December 2018. Anthropometric values and blood pressure measurements were also assessed. A standard 12-lead electrocardiogram was recorded by a unique recorder, and those were examined by electrophysiologists.

All students mean age was 12.3 ± 3.1 years (6–18 years), and 52% were boys. A total of 2900 students (192.2/1000 persons; 95% confidence interval 186–198.6) had electrocardiographic abnormalities. The rate of electrocardiographic abnormalities was higher in boys than girls (p < 0.001). Electrocardiographic abnormalities were significantly higher in thin than obese students (p < 0.001), and there was a trend towards hypertensive individuals to have more electrocardiographic abnormalities compared to normotensive individuals (p = 0.063). Based on the multivariable analysis, individuals with electrocardiographic abnormalities were less likely to be girls (odds ratio 0.745, 95% confidence interval 0.682–0.814) and had a lower body mass index (odds ratio 0.961, 95% confidence interval 0.944–0.979).

In this large-scale study, there was a high prevalence of electrocardiographic abnormalities among young population. In addition, electrocardiographic findings were significantly influenced by increasing age, sex, obesity, and blood pressure levels. This community-based study revealed the implications of electrocardiographic screening to improve the care delivery by early detection.

The standard transthoracic echocardiography has some limitations in emergent and community-based situations. The emergence of pocket-sized ultrasound has led to influential advancements.

In this prospective study, in the hospital-based phase, children with suspected structural heart diseases were enrolled. In the school-based phase, healthy children were randomly selected from six schools. All individuals were examined by experienced operators using both the standard and the pocket-sized echocardiography.

A total of 73 individuals with a mean age of 9.9 ± 3.2 years in the hospital-based cohort and 143 individuals with a mean age of 12.8 ± 2.9 years in the school-based cohort were examined. The agreements between the standard and the pocket-sized echocardiography were good or excellent for major CHDs in both cohorts (κ statistics > 0.61). Among valvular pathologies, agreements for tricuspid and pulmonary valves’ regurgitation were moderate among school-based cohorts (0.56 [95% confidence interval 0.12–1] and 0.6 [95% confidence interval 0.28–0.91], respectively). The agreements for tricuspid and pulmonary valves’ regurgitation were excellent (>0.9) among hospital-based population. Other values for valvular findings were good or excellent. The overall sensitivity and specificity were 87.5% (95% confidence interval 47.3–99.7) and 93.8% (95% confidence interval 85–98.3) among the hospital-based individuals, respectively, and those were 88% (95% confidence interval 77.8–94.7) and 68.4% (95% confidence interval 56.7–78.6) among the school-based individuals, respectively. The cost of examination was reduced by approximately 70% for an individual using the pocket-sized device.

When interpreted by experienced operators, the pocket-sized echocardiography can be used as screening tool among school-aged population.