DEAR MAYO CLINIC: After a recent echocardiogram, I was told I have a patent foramen ovale. I’m 36, and I don’t have any other medical concerns. My cardiologist said I don’t need treatment for it, but I’m still worried. Does this heart defect put me at risk for health problems? When is treatment for a patent foramen ovale necessary?
ANSWER: It certainly can be unnerving to learn you have a heart defect. But the advice your cardiologist gave you is sound. In most cases, no treatment is necessary for a patent foramen ovale. If there is evidence the patent foramen ovale is associated with low blood oxygen or recurrent strokes, then a procedure to close the defect may be recommended.
A patent foramen ovale is an opening between the two upper chambers of the heart that didn’t close completely after birth. As a fetus develops, there is a small oval flap, called a foramen ovale, in the thin wall between the heart’s upper chambers that allows oxygen-rich blood from the mother to flow to the fetus. That opening is not necessary after birth, and it normally closes during infancy. When the opening does not close, it is called a patent foramen ovale.
Patent foramen ovale is very common, occurring in about 25% of the population. Most people with the condition never know they have it because it does not cause any noticeable signs or symptoms, and it cannot be heard on physical exam. As in your case, it is most often discovered on an imaging exam that’s being done for another reason. A patent foramen ovale usually does not lead to other health problems. The only time it may become cause for concern is when something goes through the opening that should not.
For example, it is possible for a small blood clot to go through a patent foramen ovale. If that happens, the clot could block an artery in the brain and lead to a stroke or block an artery elsewhere in the body. There is also the potential for a patent foramen ovale to allow low oxygen blood that has not gone through the lungs to shunt through the heart and back into the body without picking up more oxygen in the lungs. In severe cases, that may result in low blood oxygen levels — a condition known as hypoxemia. Both of these situations are extremely uncommon.
A healthcare team may recommend a patent foramen ovale be closed if a patient has had a stroke, and no other cause of the stroke can be identified. It is important that recommendation be made in conjunction with both a cardiologist and a neurologist, though, so a comprehensive assessment of the risks and benefits of closing the hole can be completed. A patient who has persistent low blood oxygen due to shunt through a patent foramen ovale also may benefit from closure.
Closing a patent foramen ovale typically involves placing a device in the hole to hold the flap together. The body then heals around the device, sealing the opening so nothing can get through it. This procedure is performed using a minimally invasive technique in which a doctor inserts a catheter with the device on it into a vein in the groin. The catheter is guided into place in the heart, where the device is inserted through the patent foramen ovale.
A less common approach involves a surgeon closing a patent foramen ovale by opening the heart and stitching the hole shut. This surgery often can be conducted through an incision that is quite small.
Usually, however, these procedures are not necessary. If you are concerned about possible risks that could be associated with this heart defect, talk to your doctor. But be reassured that, in the vast majority of cases, a patent foramen ovale is harmless. —Peter Pollak, MD, Cardiovascular Diseases, Mayo Clinic, Jacksonville, Fla.