Patent Foramen Ovale

Patent Foramen Ovale, often called PFO, is a small flap-like opening between the two upper chambers of the heart that did not fully close after birth. Most people with a PFO have no symptoms, but in selected cases it may be linked with stroke, transient ischemic attack, or low oxygen levels and should be assessed by a heart specialist.

Overview

Patent Foramen Ovale, or PFO, is a small persistent opening between the right and left atria, the two upper chambers of the heart. During pregnancy, all babies have a natural opening called the foramen ovale that helps blood bypass the lungs before birth. After birth, when the baby begins breathing, this opening usually seals as pressure changes in the heart press the flap closed.

In some people, the flap does not seal completely. This leaves a tunnel-like or flap-like opening that may open briefly when pressure on the right side of the heart rises, such as during coughing, straining, or heavy lifting. A PFO is not usually a large hole in the heart, and it often does not affect heart function or daily life.

Most people with Patent Foramen Ovale never know they have it. It is often found during tests performed after a stroke of unclear cause, during evaluation of unexplained low oxygen levels, or incidentally during an echocardiogram. When a PFO is discovered, the main question is not simply whether it exists, but whether it is likely to be responsible for any symptoms or health event.

Symptoms

Patent Foramen Ovale usually causes no symptoms. The heart can pump normally, and oxygen levels are typically normal because the opening is small and often closed by the flap most of the time. Many people with PFO are active, exercise normally, and never need treatment.

When symptoms or complications occur, they are usually related to a right-to-left shunt, meaning blood passes from the right atrium to the left atrium. This can allow a small blood clot from the veins to bypass the lungs, which normally filter many clots, and enter the arterial circulation. If that clot travels to the brain, it may cause a transient ischemic attack or stroke.

Possible clinical situations linked with PFO include:

• Stroke or transient ischemic attack, especially when no other clear cause is found.
• Shortness of breath or low oxygen levels in rare cases, particularly when symptoms worsen upright and improve lying down.
• Migraine with aura in some people, although the relationship is complex and PFO closure is not a routine migraine treatment.
• Decompression illness in divers, where bubbles may pass through a PFO into the arterial circulation.

Symptoms such as chest pain, palpitations, fainting, or breathlessness can have many causes. A PFO may be found during evaluation, but it should not automatically be assumed to be the cause without specialist assessment.

Causes & Risk Factors

Patent Foramen Ovale is congenital, meaning it is present from birth. It develops because the normal fetal opening between the atria does not fuse completely after delivery. This is not caused by something a person did or did not do, and it is not usually related to lifestyle.

The main health concern is not the PFO itself, but whether it creates a pathway for a clot or bubble to move from the venous side of circulation to the arterial side. This is called paradoxical embolism. The risk may be higher when a person has both a PFO and a reason to form blood clots in the veins.

Factors that may increase the likelihood of PFO-related complications include:

• A previous stroke or transient ischemic attack without another identified cause.
• Deep vein thrombosis or pulmonary embolism, either current or in the past.
• Inherited or acquired clotting disorders.
• Prolonged immobility, recent major surgery, long-distance travel, or serious illness that increases clot risk.
• A large shunt or associated atrial septal aneurysm seen on heart imaging.
• Activities that repeatedly increase right-sided heart pressure, such as forceful straining or certain diving situations.

Age, blood pressure, diabetes, heart rhythm problems, cholesterol levels, smoking, and blood vessel disease also influence stroke risk. For this reason, specialists evaluate the whole person rather than focusing only on the PFO finding.

Diagnosis

Patent Foramen Ovale is diagnosed with imaging tests that show the structure of the heart and whether blood can pass between the atria. A standard transthoracic echocardiogram, performed with an ultrasound probe on the chest, may show the atrial septum and overall heart function. However, a small PFO can be difficult to see on routine imaging.

A bubble study is commonly used when a PFO is suspected. In this test, a small amount of agitated saline is injected into a vein while ultrasound images are taken. If bubbles appear in the left side of the heart shortly after reaching the right side, it suggests that there is a pathway such as a PFO allowing passage between the chambers. The patient may be asked to cough or perform a brief strain maneuver to temporarily increase right-sided pressure and reveal the shunt.

Transesophageal echocardiography may be recommended when more detailed images are needed. This test uses an ultrasound probe placed in the esophagus, close to the heart, to assess the size and shape of the PFO, the presence of an atrial septal aneurysm, and suitability for closure if needed. Transcranial Doppler ultrasound may also detect bubbles reaching the blood vessels of the brain, although it does not show the heart anatomy directly.

When PFO is found after a stroke or transient ischemic attack, diagnosis usually includes a broader evaluation. This may involve brain imaging, blood vessel imaging, heart rhythm monitoring to check for atrial fibrillation, blood tests, and assessment of vascular risk factors. The goal is to decide whether the PFO is likely to be related to the event or simply an incidental finding.

Treatment Options

Treatment for Patent Foramen Ovale depends on the person’s symptoms, medical history, stroke risk, PFO anatomy, and the results of specialist assessment. Many people with an incidental PFO and no symptoms need no procedure. They may simply be advised to continue routine medical care and manage general cardiovascular risk factors such as blood pressure, cholesterol, smoking, diabetes, weight, and physical activity.

Medication may be considered when there is concern about clot-related risk. Doctors may recommend medicines that reduce the chance of clot formation, such as antiplatelet or anticoagulant therapy, depending on the clinical situation. The choice of medication is individualized and must take into account bleeding risk, stroke history, vein clot history, other medical conditions, and current guidelines.

Catheter-based PFO closure is a minimally invasive procedure used in selected patients, most often after a stroke believed to be related to the PFO when no better cause has been found. During the procedure, a cardiologist guides a thin tube through a vein, usually from the groin, to the heart and places a closure device across the opening. Over time, heart tissue grows over the device. Patients are monitored before and after the procedure, and follow-up imaging may be used to confirm the result.

Surgical closure is rarely required for an isolated PFO, but it may be performed if the person is already having heart surgery for another reason or if anatomy is unusual. Rehabilitation, neurological follow-up, and prevention of future clotting events may also be part of care after a stroke. The right approach should always be decided by a cardiologist, and often a neurologist, after careful review of the individual case.

Living With / Prognosis

The outlook for most people with Patent Foramen Ovale is very good. A PFO often remains stable throughout life and does not limit normal activities. Many people do not need any special restrictions, although those with a history of stroke, clotting problems, or decompression illness may receive individualized advice.

Healthy cardiovascular habits are important for everyone, including people with PFO. This includes not smoking, staying physically active as advised by a doctor, maintaining a healthy weight, controlling blood pressure and diabetes, and treating abnormal cholesterol when recommended. For people at risk of vein clots, doctors may also discuss safe movement during long travel, hydration, and prevention strategies around surgery or periods of immobility.

Divers and people who work in high-pressure environments should discuss PFO with a physician experienced in diving or occupational medicine if they have had decompression illness or are planning higher-risk dives. Similarly, people with migraine should avoid assuming that a PFO is the cause; migraine management should be guided by a neurologist or qualified clinician.

After PFO closure, follow-up care is important to check healing, device position, heart rhythm, and the need for temporary or ongoing medication. Acibadem International’s multidisciplinary specialists and JCI-accredited hospitals diagnose and treat Patent Foramen Ovale for international patients, including coordinated cardiology and neurology evaluation when needed.

When to See a Doctor

A person should seek medical assessment if Patent Foramen Ovale is found during testing, especially if there has been a stroke, transient ischemic attack, unexplained fainting, low oxygen levels, or a history of blood clots. A cardiologist can explain whether the PFO appears small and incidental or whether further testing is appropriate.

Urgent medical care is needed for symptoms that may suggest stroke or transient ischemic attack. These include sudden weakness or numbness on one side of the body, facial drooping, speech difficulty, vision loss, severe imbalance, sudden confusion, or a sudden severe headache unlike usual headaches. Prompt evaluation is important because many conditions can cause similar symptoms, and early treatment can make a significant difference.

A doctor should also be consulted for unexplained shortness of breath, bluish lips or fingers, oxygen levels that fall when standing, new palpitations, chest discomfort, or swelling and pain in one leg that may suggest a vein clot. People with a known PFO who are planning major surgery, pregnancy, long-distance travel, or diving should ask whether any extra precautions are needed.

Frequently asked questions

What is Patent Foramen Ovale?

Patent Foramen Ovale is a small flap-like opening between the heart’s two upper chambers that did not fully close after birth. It is a congenital finding and is often harmless. In some people, it may allow clots to pass from the venous circulation to the arterial circulation, which can be important after certain strokes.

Is Patent Foramen Ovale the same as a hole in the heart?

A PFO is sometimes described as a small hole in the heart, but it is usually more like a flap or tunnel than a large open defect. It is different from many atrial septal defects, which are true holes in the wall between the atria. A cardiologist can explain the difference based on echocardiogram findings.

Does every Patent Foramen Ovale need to be closed?

No. Most PFOs do not need closure, especially when they are found incidentally and the person has no symptoms or clot-related events. Closure is considered only in selected situations, such as after certain strokes when specialist evaluation suggests the PFO is likely to be involved.

How is a PFO diagnosed?

A PFO is usually diagnosed with echocardiography, often combined with a bubble study to see whether bubbles can pass from the right side to the left side of the heart. Some patients need transesophageal echocardiography for more detailed images. Transcranial Doppler may also be used to detect passage of bubbles to the brain’s circulation.

Can Patent Foramen Ovale cause a stroke?

A PFO can be associated with stroke in some people if a clot passes through the opening and travels to the brain. However, many people with PFO never have a stroke, and many strokes are caused by other conditions. A careful evaluation is needed before deciding that a PFO caused a stroke.

What are the treatment options for PFO?

Treatment options include observation, medication to reduce clot risk, and catheter-based closure in selected patients. The best choice depends on the person’s medical history, stroke or clot history, PFO anatomy, and overall risk. Decisions should be made with a cardiologist and, when relevant, a neurologist.

Can someone with Patent Foramen Ovale exercise normally?

Most people with an incidental PFO can exercise normally, but advice should be individualized. People with recent stroke, heart rhythm symptoms, low oxygen levels, or clotting problems should ask their doctor before starting intense activity. Divers and people in high-pressure environments should seek specialized medical guidance.

References

• American Heart Association
• American College of Cardiology
• European Society of Cardiology
• Mayo Clinic
• National Institute for Health and Care Excellence

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.