The article presents a clinical case of acute myocardial infarction (AMI) with myomalacia and tamponade development in a patient with Loeys-Dietz syndrome, who developed a fatal outcome two weeks after the onset of respiratory infection’s symptoms. It has been noted in follow-up that the symptoms of COVID-19 infection were mild, followed by signs of lung damage in the form of viral interstitial pneumonia with acute respiratory distress syndrome. AMI with miomalacia, rupture of the right ventricle’s posterior wall, hemopericardium and tamponade developed. Important features of AMI were the rare localization (right ventricle) and the fact that the process developed without the presence of atherosclerotic lesion of coronary arteries.