Abstract Background Despite the reporting of myocarditis associated with coronavirus disease 2019 vaccination, the correlation between vaccine-related rhabdomyositis and myocarditis incidence remains undocumented. This case offers a new perspective on myocarditis, potentially associated with the coronavirus disease 2019 vaccine, possibly caused by the strong immunostimulatory effects of messenger RNA vaccination-related rhabdomyositis. Case presentation A 25-year-old male athlete of Swedish (white) ethnicity and non-Hispanic origin collapsed during a strenuous ice hockey training session after receiving his third dose of the coronavirus disease 2019 vaccine (BN162b2). He had received standard cardiopulmonary resuscitation, and the electrocardiography showed ventricle fibrillation. According to the laboratory test, elevations were observed in troponin T, aminotransferase, blood glucose, and leucocyte number. Magnetic resonance imaging indicated disseminated myocarditis. A biopsy of the heart revealed mild lymphocytic inflammation and focal myocytolysis. The patient had permanent brain damage and passed away after the breathing tube was removed. The autopsy revealed cardiac muscle necrosis and skeletal muscle rhabdomyolysis. There was a sign of massive expansion of lymphoid compartment in the gastrointestinal tract. Increased hemophagocytosis and eosinophils were seen in the lymph node and bone marrow. The specific case drew attention to a potential association between the coronavirus disease 2019 vaccine and fatal myocarditis. Conclusion We suggest that strenuous training associated with skeletal muscle damage, together with the strong immunostimulatory effect of messenger RNA vaccination, may lead to autoimmune rhabdomyositis that potentially cross-reacts with the myocardium. Athletes should be aware of the potential danger of heavy training in close proximity to vaccination or acute infections.
Wu et al. (Fri,) studied this question.