[Aneurysm of the interatrial septum. Contribution of transesophageal echography. Relation with systemic embolic complications].

The aim of this study was to evaluate the contribution of transesophageal echocardiography to the diagnosis of aneurysms of the interatrial septum and to identify the role played by this condition in unexplained systemic embolic accidents. Thirty two aneurysms of the interatrial septum were discovered in a consecutive series of 751 transesophageal echocardiograms, i.e. an incidence of 4.2 per cent. The diagnosis was possible by transthoracic echocardiography in only 9 cases (28%). Search for a patent foramen ovale by a contrast test was positive in 87 per cent of cases of aneurysm of the interatrial septum as compared with 45 per cent for patients without an aneurysm (p < 0.01). In patients in whom transesophageal echocardiography was requested for etiological evaluation of an ischemic vascular accident of embolic origin (n = 191), an aneurysm of the interatrial septum was found in 8.3 per cent of cases. In patients with no history of a systemic embolic accident (n = 560), the incidence of septums of the interatrial septum was 2.8 per cent (p < 0.01). Furthermore, 50 per cent of patients with an aneurysm of the interatrial septum had a history of systemic embolism. Transesophageal echocardiography thus appears to be superior to transthoracic echocardiography in the positive diagnosis of aneurysms of the interatrial septum and our study is suggestive of their emboligenic nature.