[Aneurysm or false aneurysm of the interauricular septum disclosed by 2 cerebral embolisms].

The authors report a case of solitary aneurysm of the interatrial septum documented by ultrasonography and angiography and revealed by two transient cerebral ischaemic accidents unexplainable by other causes. At surgery, performed later, the interatrial septum was redundant, and Botallo's foramen was about 17 millimetres in diameter, but no sacciform cavity was found. The reasons for the discrepancy between imaging techniques and operative findings and the mechanism of systemic embolism are discussed.