key: cord-0852516-mkt0oz7s authors: Isaak, Alexander; Feisst, Andreas; Luetkens, Julian A. title: Myocarditis Following COVID-19 Vaccination date: 2021-08-03 journal: Radiology DOI: 10.1148/radiol.2021211766 sha: 0d3f2f0c5ab8f7a71f815d55c6d22e50282924c5 doc_id: 852516 cord_uid: mkt0oz7s nan A healthy 15-year-old boy received his second vaccination dose (BNT162b2-mRNA SARS-CoV2, Biontech/Pfizer) and the following day he developed fever, myalgia, and intermittent tachycardia. At presentation to the hospital his electrocardiogram showed ST-segment elevation in the left precordial leads. High-sensitive cardiac troponin and C-reactive protein levels were elevated. Serology tests for cardiotropic viruses were negative. Transthoracic echocardiography showed normal myocardial function without wall motion abnormalities. Cardiac MRI at 1.5 T showed a normal left ventricular size, normal left ventricular ejection fraction and a small pericardial effusion. T2-weighted short TI inversion recovery sequences displayed focal myocardial edema involving the lateral wall, most emphasized in the basal inferolateral segment ( Figure) . Corresponding subepicardial enhancement was detected by late gadolinium enhancement imaging indicating inflammatory necrosis ( Figure) . Quantitative myocardial mapping parameters were elevated confirming the qualitatively assessed findings (Figure) . The 2018 Lake Louise criteria for the diagnosis of an acute myocarditis were fulfilled (1, 2). Furthermore, vaccine-induced unilateral axillary lymphadenopathy was also observed. Due to the close temporal relation between the mRNA SARS-CoV-2 vaccination and the onset of symptoms (one day), vaccine-induced hypersensitivity myocarditis was clinical diagnosis. The patient was discharged in stable condition after 7 days of hospitalization. Cardiac MRI characteristics of vaccine-induced hypersensitivity myocarditis are similar to other virusinduced causes of myocarditis. This case shows that clinicians should be aware of vaccine-induced myocarditis as a possible adverse effect in children with thoracic/cardiovascular complaints after mRNA SARS-CoV-2-vaccination. As children are now scheduled to be vaccinated in many countries, cases of vaccine-induced myocarditis will have been noted in association with mRNA vaccines. Vaccine associated myocarditis is rare, but more common in the young population, especially in males (e.g. Cardiovascular Magnetic Resonance in Nonischemic Myocardial Inflammation: Expert Recommendations Comparison of Original and 2018 Lake Louise Criteria for Diagnosis of Acute Myocarditis: Results of a Validation Cohort Use of mRNA COVID-19 Vaccine After Reports of Myocarditis Among Vaccine Recipients: Update from the Advisory Committee on Immunization Practices -United States Myocarditis Following Immunization With mRNA COVID-19 Vaccines in Members of the US Military