When and how to fix a 'hole in the heart': approach to ASD and PFO.

Abnormalities in the atrial septum range in severity from patent foramen ovale (PFO), a residual cardiac structure found in approximately 25% of the general population, to uncommon, complex lesions associated with significant shunt flow and heart enlargement. While correcting some of these abnormalities is beneficial, most other defects warrant correction only under very specific circumstances.