RESUMEN
INTRODUCTION: Reported cases after the post-commercialization phase of mRNA vaccines against COVID-19 have revealed that myocarditis and pericarditis may occur predominantly in male adolescents after the second dose of the vaccine. CASE PRESENTATION: We report two cases of cardiac disorders associated with mRNA COVID-19 vaccination, both of them in 15 year-old males. One of the patients presented acute pericarditis and the second one presented acute myocarditis with left ventricular dysfunction at hospital discharge. DISCUSSION AND CONCLUSION: Physicians should be aware with the typical manifestations of these cardiovascular events after the vaccination and report suspicious cases to pharmacovigilance agencies as soon as possible. The population should rely on the pharmacovigilance system that continues to recommend vaccination as the most effective strategy to reduce the negative consequences of the pandemic.