Post-COVID myocarditis in a Japanese High School student: A case report with public health reflections

Background: Myocarditis, an inflammatory condition of the heart muscle, has emerged as a potential complication following SARS-CoV-2 infection, particularly in adolescents and young adults. While globally recognized, such cases remain underreported in the Japanese school-going population, where pandemic control measures and vaccination policies have differed.Case Presentation: We report the case of a 16-year-old male high school student from Japan who presented with acute chest pain and fatigue three weeks after recovering from a mild COVID-19 infection. Diagnostic evaluations, including elevated cardiac biomarkers and cardiac MRI, confirmed the presence of myocarditis. The patient was managed with supportive care and showed gradual recovery. This case raises critical questions regarding early recognition of cardiac complications in young individuals and the implications for school-based health monitoring.Conclusion: This case highlights the importance of clinician awareness of post-COVID cardiac manifestations in adolescents. It also prompts a re-evaluation of health screening protocols in Japanese schools and underscores the need for longitudinal research on COVID-19's cardiovascular effects in youth.