Myocarditis has been increasingly recognized as a rare complication of COVID-19 mRNA vaccinations, especially in young adolescent males. According to the US Centers for Disease Control and Prevention, the incidence of myocarditis in males 16–29 years of age is approximately 10.7 cases per 100,000. Of those diagnosed with myocarditis, roughly 69% were diagnosed 3–5 days after their second vaccination. Most recent reports have shown clinical presentations consistent with chest pain, elevated cardiac enzymes, ST elevations on ECG, and further echocardiogram or cardiac MRI findings displaying mild to moderate left systolic dysfunction. Although mechanisms in the development of myocarditis are still not clear, a promising hypothesis is that myocarditis is exacerbated by a hyperimmune response to the second dose of the vaccine. Children have a robust immune response to COVID-19, which has been exemplified by increasing cases of multisystem inflammatory syndrome in children. This report will review trends seen in patients with vaccine-induced myocarditis and highlight the benefit to risk assessment of cardiovascular complications associated with COVID-19.
