Post-Acute COVID-19 syndrome (PACS) right atrioventricular and vena cava thrombus on top of a myxoma. A Case report.

Post-Acute COVID-19 syndrome (PACS) is considered to be one of the least understood post-infectious syndromes. We report a case of a 21-year-old female who had a history of SARS-CoV-2 infection and presented with a right atrioventricular thrombus associated with pulmonary embolism and thrombocytopenia. At the time of admission, she was not vaccinated against SARS-CoV-2, and her serological tests for IgG and IgM antibodies against SARS-CoV-2 were positive. The size of the thrombus measured approximately 6 × 8 × 4 cm, which also led to tricuspid valve insufficiency due to mechanical dilatation of the valve's ring. The right atrioventricular thrombus also extended up to the inferior vena cava, leading to mild congestive hepatomegaly. Moreover, during thrombectomy, the mass of the thrombus was attached to the interseptal right atrial wall. The histopathological assessment of the core mass revealed that it was a right atrial myxoma hidden inside that large thrombus. We suspect that the formation and propagation of the thrombus to that size occurs as a part of Post-Acute COVID-19 syndrome (PACS). This study reviews and discusses coronavirus disease 2019-relate to thrombus formation inside cardiac chambers in case of a cardiac tumor, like myxoma in the setting of post-acute phase COVID-19 syndrome.