Microthrombosis as a cause of fulminant myocarditis-like presentation with COVID-19 proven by endomyocardial biopsy

• Mechanisms of myocardial injury as a complication of COVID-19 have not been well understood. • We experienced a case with cardiogenic shock infected by COVID-19. • With endomyocardial biopsy, there was no sign of typical active myocarditis. • Ischemic changes were found at microvascular level accompanied by microthrombi. • Microvascular thrombotic injury is shown as a cause of fulminant myocarditis-like presentation. Myocardial injury has been reported as a complication of COVID-19. Although several mechanisms have been proposed as its cause, they are mostly based on autopsy studies, We report a 49-year-old male with COVID-19-associated myocardial injury presented like fulminant myocarditis. We performed endomyocardial biopsy on day 2 and we confirmed the presence of microthrombosis histologically. He died on day 5 due to cardiogenic shock.