I have an 11mm unrepaired atrial septal defect. it has grown larger since it was discovered in 2011. do asds ever shrink?

In children, yes: In children we do see asds get smaller with age. If this question is in regards to the adult heart, you would need to contact your cardiologist.

Not usually: Over time the atrium and septal defect can enlarge but probably never shrink without repair.

Do ASDs shrink?: No tarakaufm38, they do not shrink, but they can be closed quite easily without a surgery if they are big enough to require that. The key to deciding whether they need to be closed hinges on whether the right side of the heart (right atrium and right ventricle) are dilated from the extra blood flow going there through the asd. This dilation will resolve after device placement in the cath lab.

Possibly But...: Some asds do spontaneously close. But they are generally much smaller. An 11mm ASD is unlikely to spontaneously close, especially if it's gotten larger you mentioned.