What is patent foramen ovale?

A patent foramen ovale (PFO) is a small opening between the two upper chambers of the heart, the right and the left atrium. Normally, a thin membranous wall made up of two connecting flaps separates these chambers. No blood can flow between them. If a PFO exists, a little blood can flow between the atria through the flaps. This flow is not normal.

The condition is most important because it raises the risk for stroke. Blood clots can travel from the right atrium to the left atrium and out to blood vessels of the body. If the clot blocks a blood vessel in the brain, it can cause a stroke. These clots can also damage other organs such as the heart or the kidneys.

Everyone has a PFO at birth. It is a normal part of the circulation of a fetus. But, in most infants, this small hole naturally closes very soon after birth. But in some cases, it does not. It’s a normal finding in children but not in adults.

What causes patent foramen ovale?

Before birth, a PFO is normal. In the fetus, blood high in oxygen travels from the right atrium, across the hole between the atria, and into the left atrium. From here, the blood higher in oxygen goes out to the lower left part of the heart and out to the rest of the body. After birth, the blood high in oxygen is already in the left atrium. So it doesn't need blood from the right atrium. That's why the foramen ovale normally closes soon after birth. Healthcare providers don't know what causes the hole to stay open (patent) in some people instead of closing up.

Sometimes, PFO occurs along with other heart problems. One such condition is Ebstein anomaly. It's when the valve between the upper and lower chambers on the right side of the heart doesn't close properly. Blood can then flow backward.

What are symptoms of patent foramen ovale?

Most of the time, PFO itself causes no symptoms. Sometimes symptoms do result from the complications of PFO, like stroke.

How is patent foramen ovale diagnosed?

Your healthcare provider will ask about your past health and do a physical exam. He or she will also need tests to help make the diagnosis. These include:

• Transthoracic echocardiography, done on the skin of the chest to see how blood is moving through the heart
• Transesophageal echocardiography to take ultrasound pictures taken from the esophagus
• Multidetector CT, as an another way to view the PFO
• Cardiovascular MRI, as another way to see the PFO

Healthcare providers often pair these tests with a bubble study. In this test, the technician injects saline that has been shaken into a blood vessel. The resulting bubbles can be tracked through the heart with the above imaging tests.

Sometimes, a healthcare provider diagnoses a PFO based on tests that were needed to diagnose some other condition. Other times, the healthcare provider may be looking for a PFO. That might happen, for example, if he or she is looking for possible causes of a stroke.

How is patent foramen ovale treated?

Most PFOs require no treatment. People who have no risk factors for stroke or any history of traveling blood clots usually do not get treatment. Your healthcare provider may want to treat your PFO if you have had problems from these traveling blood clots, like stroke.

In these cases, treatment for PFOs varies. In some cases, your healthcare provider may still choose not to treat the PFO. Other options include:

• Antiplatelet medicines such as aspirin, to help prevent blood clots
• Anticoagulant medicines such as warfarin, to help prevent blood clots
• Closure of the PFO with a catheter-based procedure. A catheter is a long, thin tube inserted through a vessel.
• Closure of the PFO during heart surgery

Ask your healthcare provider what treatment plan is best for you.

What are the complications of patent foramen ovale?

Stroke is the major potential complication of PFO. People who have a PFO are slightly more likely to have a stroke than people who do not. A PFO is more likely to be the cause of stroke in a younger adult because younger people don't have as many risk factors for stroke from other causes. Stroke can cause the following symptoms:

• Numbness or weakness of the leg
• Confusion
• Difficulty seeing out of one eye
• Severe headache
• Loss of coordination

Most strokes do not result from a PFO. Even people who have a PFO often have strokes for other reasons.

A PFO can cause other complications as well. These include:

• Migraine and vascular headache
• Air embolism in scuba divers
• Heart attack (rare)
• Blood clots affecting other organ systems. For example, kidney damage may happen because a clot blocks blood flow to the kidney.
• Fat clot

How to manage patent foramen ovale

In many cases, your healthcare provider may choose not to treat your PFO directly. He or she may make suggestions about how to lower your overall risk for stroke. These might include:

• Eating a healthy diet
• Getting enough exercise and avoiding obesity
• Taking medicines for high blood pressure or high cholesterol, as needed
• Not smoking
• Getting treatment for other health conditions that increase the risk for stroke. An example is atrial fibrillation.
• Avoiding excess alcohol use or illicit drugs

Your healthcare provider might also give you tips to prevent getting blood clots in your legs. For instance, avoid sitting or standing in the same position for a long time. Make sure all your healthcare providers know about your PFO. Be sure to follow your healthcare provider's instructions about medicine and lifestyle.

When should I call my healthcare provider?

See a healthcare provider right away if you are having any symptoms of stroke. These include sudden weakness or numbness, confusion, difficulty seeing out of an eye, or loss of coordination.

Key points about patent foramen ovale

• PFO means that you have a small opening between the right and left atria of the heart. This opening normally closes soon after birth. But in many people, it does not.
• PFO itself usually does not cause any symptoms.
• PFO can occasionally result in complications. The most serious of these is stroke.
• Most people will not need treatment for a PFO.
• Some people receive treatment for PFO, especially if they have had a stroke due to a PFO. Healthcare providers may treat with medicine, procedures, or surgery.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.
• Before your visit, write down questions you want answered.
• Bring someone with you to help you ask questions and remember what your provider tells you.
• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.
• Ask if your condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if you do not take the medicine or have the test or procedure.
• If you have a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your provider if you have questions.