U.S, September 2021, Marshall et al, Pedriatrics
7 cases of acute myocarditis or myopericarditis in healthy male adolescents who presented with chest pain all within 4 days after the second dose of Pfizer-BioNTech COVID-19 vaccination. Extensive diagnostic evaluation for other myocarditis etiologies was negative. Cardiac MRI revealed late gadolinium enhancement characteristic of myocarditis. There was some suggestion of abnormal left ventricular myocardial echocardiographic strain corresponding to regions of myocardial necrosis on cardiac MRI (patient 3).