Atrial septal aneurysm as a cardioembolic source in adult patients with stroke and normal carotid arteries. A multicentre study.

BACKGROUND Atrial septal aneurysm has been considered a potential source of cardiogenic embolism for many years. The present study evaluated the prevalence and characteristics of atrial septal aneurysm in a patient population with stroke and normal carotid arteries compared to a control population without stroke. METHODS A total of 606 patients were enrolled between November 1990 and December 1996. The study group included 245 patients who had experienced cerebral ischaemic attack but had normal carotid arteries. The control group included 316 age- and sex-matched patients undergoing transoesophageal echocardiography for indications other than a search for a cardiac source of embolism. The prevalence and morphological characteristics of atrial septal aneurysm were evaluated and compared. Results We reported a higher prevalence of atrial septal aneurysm in the group with cerebral ischaemia; 68 patients (27.7%) vs 36 patients (9.9%) from the control group; P<0.001. A patent foramen ovale was detected with contrast injection in 69.2% of the patients with atrial septal aneurysm. Atrial septal aneurysm predicted the presence of a patent foramen ovale (odds ratio of patent foramen ovale 4.2; 95% CI 1.03-9.8). Multivariate analysis showed that atrial septal aneurysm was an independent predictor of an embolic event. In the 95% of patients with atrial septal aneurysm and cerebral ischaemia aged less than 45 years, transoesophageal echocardiography did not detect a source of embolism other than an associated patent foramen ovale. CONCLUSIONS The prevalence of atrial septal aneurysm in patients with cerebral ischaemia and normal carotid arteries was 27.7%, higher than the control group. Atrial septal aneurysm was frequently associated with patent foramen ovale. In patients less than 45 years old, atrial septal aneurysm was the only potential cardiac source of embolism detected with transoesophageal echocardiography.