Background <p>Heart diseases in children and teenagers, including congenital and non-congenital cardiovascular diseases remain major causes of illness and death worldwide. Yet, long-term patterns and recent changes are poorly understood. This study explores global trends and inequalities in their burden.</p> Methods <p>We used data from the Global Burden of Disease 2021 study to examine incidence, prevalence, mortality, and disability-adjusted life years among people younger than 20 years across 204 countries from 1992 to 2021. We examined trends over time and used statistical models to see how age, historical period, and year of birth influence the risk of pediatric heart diseases.</p> Results <p>Here we show that in 2021, there are 2.64 billion people under 20 years of age, mainly in countries with lower income and education levels. Heart diseases cause 309,000 deaths and 28.7 million years of healthy life lost. Congenital heart disease accounts for most deaths, while non-congenital heart disease is more common overall and rises by over one-third since 1992, with sharper increases after 2019. Death rates in poorer regions are up to eight times higher than in richer regions. Although the overall death rate declines by 55 %, adolescents and individuals born more recently face increasing risk for non-congenital conditions.</p> Conclusions <p>The burden of heart disease in the young remains heavy, with significant regional and socioeconomic inequalities. Stronger prevention, earlier detection, and better health care are urgently needed, especially in disadvantaged regions and in the years after the coronavirus pandemic.</p>