Low Incidence of Cerebrovascular Events in Patients with Incidental Atrial Septal Aneurysm.

OBJECTIVES: The purpose of our investigation was to describe the echocardiographic characteristics of an atrial septal aneurysm (ASA) and associated cardiac abnormalities, to determine whether any echocardiographic characteristics are associated with cerebrovascular events, and to compare the cerebrovascular risk of ASA when it is an isolated and incidental finding with ASA associated with other cardiac abnormalities and diagnostic indications, including a cardiac source of embolus. METHODS: In 1605 consecutive patients referred for transesophageal echocardiography during open heart surgery, we identified 78 patients with ASA as an incidental finding (Group I). During the same period, this anomaly was found in 39 of 8014 consecutive patients referred to the echocardiographic laboratory for various diagnostic reasons (Group II). The frequency of cerebrovascular events and ASA characteristics was compared between these two groups. RESULTS: A total of 117 patients with ASA was included in the study: 60 males and 57 females with a mean age of 66.7 +/- 9.1 years. There were no significant differences in the echocardiographic characteristics of ASA or associated cardiac abnormalities between these two groups; no intracardiac or ASA associated thrombi were detected in either group. While only 6.4% of Group I had a clinical event, 23% of patients in Group II had a stroke or transient ischemic abnormality. CONCLUSIONS: The morphological characteristics of ASA and associated cardiac abnormalities do not distinguish patients at risk for cerebrovascular events. Although the presence of ASA may be a risk factor for embolic strokes, this risk is lower than previously thought.