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Patent Foramen Ovale

While we are in the womb our blood supply, for the most part, bypasses our lungs. We get the oxygen that we need to grow from our mothers through the placenta. To avoid the lungs, there is a flap-like opening, called the foramen ovale, between the two upper chambers of our developing hearts. (Read about "The Heart & Its Valves")

When we are born and start to breathe, the difference in pressure from one side of the heart to the other pushes the flap closed. Within the first few days and weeks of life, the hole is permanently sealed. This doesn't happen all the time however. When the hole remains open, it is called a patent foramen ovale (PFO).

The National Stroke Association (NSA) estimates that one in five Americans have a PFO. Another group, the Diver Alert Network (DAN), has an even higher estimate saying, as many as 30 percent of the population has a PFO.

A PFO may be a problem if other congenital heart defects are present. (Read about "Congenital Heart Defects") But most people have no problems, and in fact never even know they have a PFO. PFO is however considered a risk factor for at least two things:

• stroke (Read about "Stroke")
• decompression sickness (DCS)

The opening potentially allows clots from other parts of the body to pass through and travel to the brain (Read about "The Brain") and block a blood vessel there, resulting in a stroke. DAN says that the risk of developing DCS when diving with a PFO is between two and five times higher. The U. S. military screens many of its personnel for PFO, especially divers and pilots.

PFO's are usually discovered after some sort of event, like a stroke. An echocardiogram, which is an ultrasound of the heart (Read about "Ultrasound Imaging"), is one of the tools used to diagnose a PFO. Other tools include x-ray and electrocardiogram. (Read about "X-rays" "EKG - Electrocardiogram") Once the PFO is diagnosed, you can discuss with your healthcare provider appropriate treatment. Currently medications, mainly to lower the risk of clots forming and resulting in a stroke, are a main form of treatment. Closing the hole, either by open surgery or by inserting an implanted device to close the PFO, is another option.

Related Information:

    Cardiovascular Tests