An atrial septal aneurysm is an atrial septum that is bulging, abnormally enlarged and mobile, explains About.com. The atrial septum is the membrane that separates the upper chambers of the heart. When the atrial septum encroaches into one or both chambers during a heartbeat, it is considered an aneurysm.
Atrial septal aneurysms are rare but easily recognized deformities of the heart, claims the Annals of Pediatric Cardiology. Usually, the significance of this is uncertain. Doctors diagnose atrial septal aneurysm is done by using transthoracic and transesophageal echocardiography. Though many cases of atrial septal aneurysms are benign, it is possible for some of them to cause a stroke.
In the general adult population, only about 2.2 percent of people have this anomaly, states the Annals of Pediatric Cardiology. Younger patients have a greater chance of developing this condition; however, anyone who has an atrial septal aneurysm is at risk for an ischemic stroke. This includes those in the pediatric age group. More studies need to be done to find the connection between the abnormalities in the heart, such as atrial septal aneurysm and stroke. It is possible that a thrombus formation on the left side of the atrial septal aneurysm is responsible for this.