Overview of Atrial Septal Defect and Patent Foramen Ovale
Atrial septal defect (ASD) and patent foramen ovale (PFO) are two types of holes or defects that can occur between the upper two chambers of the heart.
Atrial septal defect (ASD) – This birth defect is fairly common. With ASD, there is a hole in the wall between the two upper chambers of the heart (the atria). The hole allows oxygen-rich and oxygen depleted blood to mix, and overfills the (lower-pressure) right atrium with blood. As a result, too much blood flows into the right ventricle and lungs. Your heart has to work harder, and your lungs can be damaged.
Patent foramen ovale (PFO) – Fetuses have a normal opening (called a foramen ovale) between the left and right atria of the heart. But if this opening fails to close naturally soon after birth, the result is an open patent foramen ovale, or PFO. Most of the time, this defect doesn't cause significant health problems, and doesn't require treatment. When a PFO is serious enough to cause problems, healthcare providers may recommend a procedure to close the hole.