Congenital aortic sinus aneurysm causing sudden unexpected death in a 56-year-old woman.

Sudden unexpected death due to hemopericardium generally has 2 main causes, rupture of the ascending aorta or rupture of a transmural myocardial infarct. We report an unusual cause of fatal hemopericardium in a 56-year-old woman that occurred in the setting of a motor vehicle mishap.At autopsy, 300 mL of blood were present in the pericardial sac, due to rupture of a previously undetected congenital aortic sinus aneurysm.