If you’ve come across the term Patent Foramen Ovale or PFO for short you’re not alone in wondering what it actually means and whether it could be relevant after COVID-19. This guide explains the basics in plain language and outlines what to discuss with your GP if you think it might apply to you.
What Is a Patent Foramen Ovale (PFO)?
A Patent Foramen Ovale is a small flap-like opening between the two upper chambers of the heart (called the atria). Everyone has this opening before birth — it allows blood to bypass the lungs while a baby is in the womb. Normally, it closes soon after birth.
In some people, though, it stays open. That’s called a PFO. Most people with a PFO never know they have one, and it usually causes no problems at all. However, in certain situations, it can allow a small amount of blood to pass the “wrong way” through the heart from the right side to the left without going through the lungs first.
In rare cases, this can increase the risk of small blood clots travelling through the bloodstream (a phenomenon called a paradoxical embolism), which in turn has been linked with some strokes or episodes of unexplained breathlessness.
How COVID-19 Might Make PFO Symptoms More Noticeable
COVID-19 affects both the lungs and the cardiovascular system, and in some cases, it can unmask or worsen problems that were previously silent.
Some case reports and studies have found that:
- Increased strain on the heart and lungs during or after COVID-19 can make the pressure in the right side of the heart rise temporarily. This pressure shift can cause a PFO to open more easily, allowing blood to move through it when it normally wouldn’t.
- A few patients recovering from COVID-19 have experienced unexplained low oxygen levels (hypoxaemia) or shortness of breath during activity (exertional dyspnoea), which later turned out to be linked to an undiagnosed PFO. In those cases, closing the PFO helped restore normal oxygen levels.
- In people who were severely ill with COVID-19 and needed ventilation, studies have shown that mechanical pressure in the lungs can sometimes push blood through an existing PFO, reducing oxygenation efficiency.
It’s important to stress that this is still an emerging area of research, and not everyone with long COVID or fatigue has a PFO-related problem. But understanding this link can help guide sensible next steps if symptoms don’t add up.
How Common Is a PFO?
A PFO is very common present in roughly one in five adults (16–25%). Most people will never know it’s there. However, in people with existing cardiovascular stress or certain post-COVID symptoms, it might become more noticeable.
Some studies of post-COVID patients have noted ongoing fatigue, palpitations, or shortness of breath, and while there can be many causes, in a few cases, a previously unnoticed PFO was contributing to these issues.
How a PFO Is Diagnosed
If your doctor suspects a PFO might be playing a role in your symptoms, they may arrange a few simple, non-invasive tests:
- Echocardiogram (heart ultrasound): This visualises the structure of the heart and can often spot a PFO.
- Bubble study: A small amount of saline (salt water) is mixed with air and injected during an echocardiogram to check whether tiny bubbles cross from the right to the left side of the heart.
- Oxygen monitoring and exercise tests: These can help detect drops in oxygen levels during movement, which may suggest a shunt (abnormal blood flow) through a PFO.
Your GP can refer you for these investigations if needed, usually to a cardiologist.
Management and Treatment Options
If a PFO is discovered, the next step depends entirely on whether it’s actually causing symptoms or complications. Many people don’t require any treatment at all.
For those who do have persistent problems such as unexplained low oxygen levels, stroke of unknown cause, or severe exertional breathlessness closure may be considered.
There are two main approaches:
- Percutaneous closure: A small, minimally invasive procedure where a thin tube (catheter) is passed through a vein to place a tiny device that seals the opening.
- Surgical closure: Much less common, and usually done only if a person is already having heart surgery for another reason.
A cardiologist would help decide if either approach is suitable, based on test results, overall health, and symptom history.
Managing Post-COVID Fatigue and Circulation Symptoms
Even if your symptoms are not directly caused by a PFO, these general principles can help support cardiovascular recovery after COVID-19:
- Start gently: Build up activity slowly especially if you suffer of PEM and rest before you feel exhausted.
- Monitor symptoms: Keep an eye on heart rate, oxygen levels, and how you feel during exertion.
- Stay hydrated and nourished: Dehydration can worsen fatigue and circulation symptoms.
- Check in with your GP: Especially if symptoms such as shortness of breath, dizziness, or palpitations persist or worsen.
If your GP suspects a PFO or another cardiovascular issue, they can refer you for specialist testing.
When to Seek Medical Advice
You should speak to a healthcare professional if you experience:
- Ongoing shortness of breath or low oxygen readings
- Persistent fatigue or dizziness after even light activity
- Unexplained palpitations or episodes of near-fainting
- A previous unexplained stroke or clotting event
These symptoms don’t necessarily mean you have a PFO there are many possible causes but it’s worth a proper medical assessment.
Disclaimer
This article is for information only and does not constitute medical advice. It should not be used to diagnose or treat any health condition. Always consult a GP or qualified healthcare professional if you have concerns about your heart health, recovery after COVID-19, or possible PFO-related symptoms.
Long Covid Journey 