PFO on Echo: What Does a Patent Foramen Ovale Mean?

PFO on an echo means the scan showed, or a bubble study suggested, a small flap-like opening between the two upper chambers of the heart. Everyone has this opening before birth, and it usually closes in early childhood. When it stays open, it is called a patent foramen ovale.

It is common. The American Academy of Neurology (AAN) says the connection stays open in about one in four people, and Cleveland Clinic estimates up to one in four adults have one. Most people never know they have it, because it usually causes no symptoms.

This guide explains the report wording and the questions worth asking. It cannot tell you whether a PFO is linked to any symptom or event in your own case.

A PFO finding does not change the advice for stroke warning signs. The NHS uses FAST: face drooping on one side, inability to raise both arms and keep them up, and slurred or confused speech. Time matters, so call your local emergency number straight away.

Other sudden signs listed by the NHS include weakness or numbness on one side of the body, blurred vision or sight loss, confusion, dizziness or falling, and a severe headache. Get emergency help even if the symptoms stop after a short time. Do not drive yourself to hospital, and do not wait for a planned follow-up appointment.

Before birth, blood bypasses the lungs, and this opening lets it pass from the right upper chamber to the left. After birth the flap normally seals. In some people it does not seal completely, leaving a small connection between the two sides.

The AAN describes a PFO as presenting a low risk of stroke and says that, commonly, it does not cause any problems. Cleveland Clinic notes that most people with a PFO will not need treatment.

If your PFO was found by chance, during an echo done for another reason, ask whether it needs any follow-up at all and whether it changes anything about your care. A chance finding is not the same situation as a PFO found during tests after a stroke.

A standard echo uses ultrasound over the chest, which the NHS calls a transthoracic echocardiogram. A small PFO can be hard to see this way, so a bubble study may be added.

In a bubble study, saline is shaken to make tiny bubbles and injected through a small tube in an arm vein. An NHS hospital leaflet explains that the team watches whether bubbles cross from the right side of the heart to the left. You may be asked to cough, sniff or strain by blowing against a closed airway, called the Valsalva manoeuvre, which you can practise beforehand.

If more detail is needed, a transoesophageal echo passes a thin probe down the throat to give a more detailed image of the heart. Cleveland Clinic also describes transcranial Doppler, an ultrasound of the head that can detect bubbles reaching the brain's blood vessels.

• Check which test you had: a standard echo, a bubble study, a transoesophageal echo, or more than one.
• Check whether the report describes the size of the shunt or other features, and ask what these mean for you.
• Results may need further review, so the full report may come later than the scan.

In some people, a PFO can let a blood clot cross from the right side of the heart to the left and travel to the brain. Cleveland Clinic notes that a PFO is often found while doctors look for the cause of a stroke or transient ischaemic attack (TIA). It also states that about 3 in 10 strokes are cryptogenic, meaning no cause is found, and that as many as 1 in 2 people under 60 with this kind of stroke have a PFO.

Finding a PFO does not prove it caused a stroke. The AAN stresses that doctors with stroke expertise should rule out other causes first.

Cleveland Clinic lists migraines or migraine-like headaches among possible symptoms when a PFO lets a large amount of blood through, which it describes as rare. Whether a PFO matters for your headaches is a question for your specialist; a PFO finding alone does not explain them.

Closure is usually discussed after a stroke thought to be caused by the PFO, not for a PFO found by chance. The AAN's 2020 patient summary says that for some patients, particularly those younger than 60 who have had such a stroke, closure lowers the risk of another stroke more than medical treatment alone.

Closure is usually done with a catheter that places a device through the blood vessels into the heart, without open surgery. The AAN notes a small risk of complications, including an abnormal heart rhythm, and says patients and doctors should weigh the risks and benefits together. For people who do not have closure, doctors may recommend medicines that help prevent blood clots. Cleveland Clinic adds that treatment may also be considered for people with a history or high risk of clots.

Bring the full echo report to the appointment. These questions can help you understand what the finding means for you.

• Why was my echo done, and does the PFO finding answer that question?
• Was the PFO seen directly, or found with a bubble study? Do I need any other test?
• Is my PFO thought to be related to any symptom or event I have had?
• If I had a stroke or TIA, has the cause been identified, and have other causes been ruled out?
• Is closure being considered for me? What are the possible benefits and risks?
• Do I need any follow-up, and who will contact me about it?

On SameCase, patients and verified doctors share de-identified cases. Reading how others with a PFO finding described their echo, bubble study and follow-up discussions can help you notice what to ask and which details to bring.

Other people's cases cannot tell you whether your PFO matters or what treatment you need. We encourage you to take your questions to the clinician who knows your full history.