Is it just another case of vaccine-induced myocarditis? A case report and key insights.

Background: As the number of individuals receiving the coronavirus disease 2019 (COVID-19) vaccine continues to rise, we have observed a concurrent increase in myopericarditis cases within the general population. This case serves as a reminder of the necessity to approach such occurrences with an open mind. Additionally, it underscores the importance of employing multi-modal imaging techniques alongside a collaborative, multi-disciplinary approach when addressing complex medical cases.

Case summary: We present a case of a woman in her 50s attending the emergency department with pyrexia, lethargy, and chest pain following the AstraZeneca COVID-19 vaccine. She had a background of systemic lupus erythematosus that was treated with immunosuppressive medication.Initial assessments revealed abnormal electrocardiogram, elevated troponin, and raised inflammatory markers. A diagnosis of likely vaccine-induced myopericarditis was made. However, blood cultures revealed Listeria monocytogenes, and cardiac imaging confirmed a right atrial (RA) thrombus that was considered to be infected. Subsequently, she was treated for Listeria myopericarditis and infected thrombus with intravenous antibiotics and anticoagulation. The patient did not wish for any invasive investigations given her clinical improvement. This is the first case of Listeria-related myopericarditis with an infected thrombus in the RA. We saw the full resolution of RA mass with medical management.

Discussion: This case highlights the importance of multi-modality imaging techniques to facilitate the diagnosis of Listeria-related myopericarditis accompanied by an infected thrombus. It also emphasizes the importance of conducting interval scanning and follow-up assessments to ensure the resolution of the disease. To improve diagnostic accuracy, an endomyocardial biopsy can also be considered.