[Interatrial septal aneurysm. Echocardiographic diagnosis].

Interatrial septal aneurysm is a rare abnormality and can now be diagnosed by echocardiography. We report the case of a 52 year old woman in whom this condition was diagnosed after an embolic cerebrovascular accident. M mode recordings showed a linear echo in the left atrial cavity in early and mid systole. The aneurysm was directly visualised by 2D echo as a hemispherical bulge in the mid portion of the interatrial septum, which was mobile and had a to-and-fro motion between the two atria in relation to the different phases of the cardiac cycle. The diagnosis was confirmed by angiography, and at surgery. A feature of this case was the close correlation between echocardiographic, angiographic and operative findings. The pathogenesis of this type of aneurysm remains conjectural as does its role in the production of cerebral embolism, the evidence for which was circumstantial in the absence of other demonstrable causes and in the light of previously reported cases.