Atrial septal aneurysms are commonly seen in the setting of an ASD, and having both does increase the risk of stroke (somewhere on the order of 7-15% lifetime risk). This does not mean that everyone with these anomalies will have a stroke, and it doesn't say anything about needing a pacemaker (your doctor may have been referring to a different indication for a pacemaker, because ASDs and ASAs aren't usually a big reason for pacemaker implantation). The treatment options for these anomalies include antiplatelet medication to decrease the risk of clot formation (aspirin, warfarin) versus surgical or percutaneous correction. There is no clear evidence that closure is better than medical therapy because it is not clear that strokes that occur in this population are actually related to the defect. Generally, they are not closed in asymptomatic patients, and some studies have even shown that surgical closure may actually increase the risk of psot-operative stroke.
Bottom line, if you are asymptomatic, there is probably no need to fix the defect, but you should take aspirin.
Thank you. I'm not real familiar with correct terminology, but my arythmia is not good because of the aneurysm, which was determined by EKG tests. That is why I was told I would have to have a pacemaker. Does that make sense? Thanks for your feedback!!