Acute Myocarditis after COVID-19 vaccination: A case report.

Introduction The etiology of myocarditis often remains undetermined. A large variety of infectious agents, systemic diseases, drugs, and toxins can cause the disease. We report the case of a 19-year-old man who developed myocarditis three days after Pfizer-BioNTech COVID-19 booster vaccination. Case report A 19-year-old man, presenting with troponin-positive acute chest pain, was referred to our department. He had received the Pfizer-BioNTech COVID-19 vaccine three days prior to his admission. The diagnosis of acute myocarditis was confirmed by cardiovascular magnetic resonance imaging. Patient hemodynamic status remained stable during hospitalization. The left ventricular ejection fraction was preserved during hospital stay and at one-month follow-up. We found no evidence for another infectious or autoimmune etiology. Conclusion Although imputability of the vaccine cannot be formally established on the basis of this case report, the findings raise the possibility of an association between mRNA COVID-19 vaccination and acute myocarditis.