Multiple pseudoaneurysms in complicated infective endocarditis: importance of the Yin-Yang sign and multimodality imaging-case report.

Background: Infective endocarditis (IE) continues to show a rising global incidence and significant associated mortality. Among its complications, pseudoaneurysms (pAs) are peri-annular lesions resulting from localized tissue destruction caused by infection, leading to a focal dilatation. These lesions usually occur as isolated findings, and the presence of multiple pAs is rare. Importantly, pAs are recognized predictors of in-hospital mortality. Case summary: We describe three distinct patients exhibiting IE complicated with multiple pAs with particular and unique features. Patient 1 is a 49-year-old woman with pre-existing bicuspid aortic valve (BAV), with fever and dyspnoea; two pAs were identified (in the aortic root and mitral-aortic intervalvular fibrosa) and were successfully treated with surgical resection. Patient 2 is a 51-year-old man with past history of a Bentall procedure, presented with 3-month history of fever. Two large pAs were found in the aortic root; despite successful surgical repair, the patient died secondary of refractory vasoplegic shock. Patient 3 is a 3-year-old boy, with a known BAV with 4 weeks of high-degree fever. Three pAs were identified (two in the aortic root and one in the mitral valve) along with two other congenital heart defects. Unfortunately, despite full medical treatment, patient died due to refractory cardiogenic shock. Discussion: Multimodality imaging served as a cornerstone for the accurate diagnosis, anatomical localization, and extension of pAs in all three patients. Echocardiography helped to reveal the echo-free spaces with systolic expansion and diastolic collapse, a feature that was also observed in the cardiac angio-computed tomography. Notably, the presence of the Yin-Yang sign on colour Doppler imaging served as a key diagnostic clue and should be carefully sought when evaluating patients with IE.