A patent foramen ovale is an opening that some adults have between the top two chambers of their hearts. Everyone has this opening early in life, but it often seals during infancy. In some people, though, it doesn’t. Researchers do not currently understand why some close and others don’t.
Babies never show symptoms of this condition, but PFO is sometimes found alongside other heart conditions. They may have other complications when PFO is combined with these conditions.
If you have PFO as an adult, there is a good chance that you won’t even know. Most people don’t have symptoms. Rarely, though, patent foramen ovale symptoms manifest as migraines, shortness of breath when getting up and standing, and a higher risk for certain kinds of strokes.
What Is a Patent Foramen Ovale?
Your patent foramen ovale is located in the area of the heart between the left and right atria—the two upper chambers of the heart. It’s open when babies are in the womb and usually closes within the first year of life. It’s called a patent foramen ovale when the opening doesn’t close when it should. The cause is unknown, but genetics could play a role.
By age six month old, 50% of the openings have closed, and by adulthood, 75% of them have closed. This means that one-quarter of the adult population has a patent foramen ovale.
The opening in a PFO is not a completely open tunnel. It has a flap over it.
The area is open when babies are in the womb because it allows for proper blood flow. Blood flow is different in the womb because oxygen-filled blood comes from the umbilical cord instead of the lungs, where you get oxygen after you’re born. The opening allows the blood to move from the veins, through the right atrium, directly into the left atrium.
When you’re born, you start to use your lungs and your blood flow redirects. In most cases, the pressure from your heart pumping in this new way is enough to close the opening between your left and right atria.
How Is Patent Foramen Ovale (PFO) Diagnosed?
The most common way to diagnose a patent foramen ovale is with an echocardiogram — a type of ultrasound for your heart. This allows your doctor to use soundwaves to see the different parts of your heart by moving a special wand over your chest.
Sometimes, you can easily see a PFO with a basic echocardiogram. When it’s difficult to see, though, there are other variations on echocardiograms that can help your doctor see if you have a PFO. They include:
- Transesophageal echocardiogram. This is similar to a normal echocardiogram. For this procedure, the device that produces the sound waves is on a thin tube that is inserted down your throat and into your stomach. This is currently the most accurate way to diagnose a PFO.
- Bubble test. For this method, your doctor will inject you with a saline — salt and water — solution. This makes small bubbles show up on an echocardiogram. Your doctor will be able to see the bubbles move from the right to the left side of your heart.
- Color Flow Doppler. Some echocardiograms can show different colors for objects moving at different speeds and can show the directions of movement. When the sound waves bounce off of the blood cells moving through the heart, your doctor can tell if they are moving from the right to the left atria, which only happens when the PFO is open.
Are There Complications of a Patent Foramen Ovale?
Most of the time, PFO is symptomless in adults, but there are some rare complications that are associated with the condition. These include:
- Atrial septal aneurysm. The top part of the septum—the wall between the left and right sides of the heart—can start to bulge into one or both of the atria. This is a condition that is sometimes seen with PFO.
- Migraines. There is no understood link between PFO and migraines, but adults with PFOs sometimes have an increased chance of having migraines — particularly ones where halos form in your vision.
- Cryptogenic Strokes. This is a kind of stroke that doesn’t have another identifiable cause. People with this kind of stroke are two times more likely to have a PFO than the general population. In these cases, it’s likely a thromboembolic stroke, where a blood clot that forms elsewhere in your body such as your leg moves into your heart and through the PFO. From there, it can make its way to the brain and cause a stroke.
- Platypnea orthodeoxia. This is a condition where people suffer from shortness of breath and low blood oxygen levels. If too much blood flows through the PFO, then it doesn’t reach the lungs to pick up a fresh supply of oxygen. This can leave you dizzy and short of breath, particularly when standing up.
- Increased risk of decompression sickness. This complication is unique to scuba divers. Divers have to deal with a condition called decompression sickness. This happens when they rise from deep, pressurized areas too quickly. Sometimes, though, this sickness is more spontaneous, seemingly uncaused by what the diver did. In two-thirds of these cases, these divers have PFOs.
What Is the Treatment for a Patent Foramen Ovale?
Most of the time, a patent foramen ovale doesn’t need to be treated. But there are surgeries to close the opening, especially for people with PFO who are younger than age 60 and have already survived a stroke.
The most common surgery is to insert a closure device using a thin, flexible tube that goes through your groin to your heart. Your doctor moves it into place by watching it with an echocardiogram, then closes the hole by applying pressure with the device. Open heart surgery is only used to stitch the opening closed when you need the surgery to fix another heart condition at the same time.
Complications from this surgery are very unlikely—less than 1%—but can include tears to the heart or blood vessels. Also, 2% to 5% of all patients temporarily develop an irregular heartbeat after this surgery.
Your doctor may recommend a blood thinner if you have already had a stroke, or medicine to prevent blood clots from forming in your body.
