Sinus of Valsalva Aneurysm and Infective Endocarditis Involving a Bicuspid Aortic Valve in an Infant With Trisomy 21.

A 19-month-old girl with trisomy 21 and a congenitally bicuspid aortic valve died following a short febrile illness. Autopsy disclosed pericarditis, epimyocardial abscess, infective endocarditis, and a sinus of Valsalva aneurysm. Microscopy demonstrated continuity between the aortic wall and valve leaflet, consistent with an acquired aneurysm. Abnormal hemodynamics associated with the valve malformation likely facilitated endocarditis.