Multimodality imaging and histopathology in a young man presenting with fulminant lymphocytic myocarditis and cardiogenic shock after mRNA-1273 vaccination.

A 38-year-old man presented with several days of chest pain and shortness of breath 8 days after receiving the first dose of an mRNA-1273 vaccine. The patient was found to have new left ventricular ejection fraction of 10% in the setting of hypotension and cardiogenic shock requiring mechanical support with an axial flow catheter pump. The presentation was concerning for acute fulminant myocarditis secondary to an inflammatory response from the recent mRNA-1273 vaccine. The patient was treated with pulse dose steroids for 3 days, ultimately leading to haemodynamic recovery and removal of mechanical circulatory support. Endomyocardial biopsy was performed and showed focal lymphocytic interstitial infiltrate with myocyte damage consistent with lymphocytic myocarditis. The patient had improvement of cardiac function which was seen on serial imaging.