Question: what is the difference between patent foramen ovale and atrial septal defect?
Answer: Patent foramen ovale (PFO) and atrial septal defect (ASD) are congenital (present-at-birth) conditions of the heart. PFO occurs when there is a flap-like hole in the heart wall (septum). ASD occurs when there is a hole in the heart wall that separates the top two chambers of the heart.