Two asymptomatic COVID-19–positive athletes (3%) met criteria for myocarditis2; 1 athlete had pericarditis. These athletes had normal electrocardiograms, troponin I, and echocardiograms with strain. Both athletes with myocarditis had normal left ventricular ejection fraction by initial CMR; however, 1 athlete developed new left ventricle dysfunction (left ventricular ejection fraction, 45%) on a follow-up echocardiogram performed for worsening dyspnea. COVID-19–positive athletes had increased volumes and mass when compared with healthy controls, consistent with athletic remodeling. Most standard CMR parameters were similar between COVID-19–positive athletes and athletic controls. Focal LGE isolated to the inferoseptal right ventricle insertion was present in 22% of COVID-19–positive athletes, compared with an identical LGE pattern in 24% of athletic controls.

COVID-19–positive athletes had elevated myocardial T2 relaxation times in all myocardial segments compared with healthy controls; however, only the midseptal T2 was significantly elevated compared with athletic controls. Similarly, midseptal extracellular volume was elevated in COVID-19–positive athletes compared with athletic controls. Mild segmental increases in T1, T2, or extracellular volume were found in 39% of COVID-19–positive athletes, 13% of athletic controls, and 8%