Instituto SENAI de Inovação (ISI) em Sistemas Avançados de Saúde, Centro Universitário. Conselho Nacional do Brasil (CNPq).A 23-year-old man started with chest pain 8 h after his first Pfizer-BioNTech COVID 19 vaccination. ECG evaluation showed sinus tachycardia with ST-segment elevation in D1, AVL, V5, and V6, the findings compatible with acute subepicardial myocardial damage. However, cardiac MRI documented myocardial fibrosis, with cardiac late enhancement non-ischemic pattern with diffuse edema. He had no other symptoms to suggest another etiology than the vaccination. The patient was hospitalized and received corticosteroid (prednisolone) daily. Then, 2 weeks after hospitalization, all laboratory parameters and ECG were normal and the patient was discharged from the hospital. The patient had a history of Wolf-Parkinson White that was corrected with ablation when he was 11 years old. This report calls attention to myocardial adverse reaction risk for mRNA COVID-19 vaccines for people with a previous cardiac disease history.