Introduction: Purulent pericarditis is uncommon and portends a substantial risk of mortality associated with pericardial tamponade and septic shock. Rarely, this infection spreads to the aorta and forms a pseudoaneurysm, which carries a high rupture potential and thus a high mortality risk. We describe the case of a patient with MRSA pericarditis who rapidly developed a mycotic aortic aneurysm.
Description: A 61-year-old man with a history of methicillin-resistant Staphylococcus aureus cellulitis presented with a week of positional chest pain and dyspnea. His vitals and exam were unremarkable. CT angiography showed no evidence of pulmonary embolism. Diffuse ST segment elevations on electrocardiography were concerning for pericarditis and transthoracic echocardiography revealed a large pericardial effusion with tamponade physiology. Pericardiocentesis removed 600 mL hazy fluid that grew MRSA, which was treated with Vancomycin. Repeat imaging done two days later showed a recurrent, large pericardial effusion so a pericardial window procedure was done, with removal of 500 mL purulent fluid. Four days after the first scan, a repeat CT angiogram was obtained showing a new lobular pseudoaneurysm at the anterior aortic arch. Urgent cardiac surgery was planned; however, he unexpectedly suffered a cardiac arrest. Emergent pericardiocentesis and opening of the pericardial window were attempted, but no signs of tamponade were seen. His rhythm degenerated from PEA to asystole and CPR was halted. Autopsy confirmed a 1 cm erosion at the aortic root consistent with pseudoaneurysm rupture.
Discussion: In the antibiotic era, purulent pericarditis is rare and typically presents with florid sepsis, though there are sparse reports of patients presenting with only vague symptoms. Similarly, aortic mycotic aneurysms are scarcely seen and the overlap between the two is even more uncommon. When they do coexist, they are usually discovered in tandem; however, our patient’s pseudoaneurysm developed over only a few days. As such, it is crucial to be aware of this possibility in patients with bacterial pericarditis, especially those who have undergone invasive treatments that can increase the risk of aortic translocation. Management requires prompt surgical or endovascular repair and the consequences of rupture are devastating.
