U.S, 10 August 2021, Rosner et al, Circulation
A case series of 7 patients hospitalized for acute myocarditis-like illness after COVID-19 vaccination, from 2 US medical centers in Falls Church, VA, and Dallas, TX. Six patients received an mRNA vaccine (Moderna or Pfizer/BioNTech), and 1 received the adenovirus vaccine (Johnson and Johnson). Echocardiograms showed left ventricular ejection fraction ranging from 35% to 62%, with 5 of 7 having some degree of hypokinesis. Multifocal sub-epicardial late gadolinium enhancement was present in 7 of 7 patients and additional midmyocardial late gadolinium enhancement was 4 of 7 patients.