What is a patent foramen ovale?

The foramen ovale (say "fuh-RAY-men oh-VAL-ee") is an opening in the heart's septum. This is the part that separates the upper right and left chambers (atria) of the heart. In a fetus, this opening has a flap of tissue that acts like a one-way door—it allows blood to flow to the left side of the heart without going to the lungs. It is kept open by the pressure of the blood that passes through it.

Normally, when a baby is born and takes a first breath, blood starts to flow through the lungs. The foramen ovale usually closes after birth. But sometimes it stays open and is called a patent (say "PAY-tunt") foramen ovale, or PFO.

A PFO usually doesn't cause problems as the person gets older. But sometimes it can lead to problems such as a stroke.

How is a PFO diagnosed?

Your doctor will ask you about your health history. You may also get some tests. These may include a special echocardiogram of your heart. This test uses bubbles and images to look for the hole in the septum of the heart.

How is it treated?

Treatment is a catheter procedure or surgery to close the opening in the heart. This may be an option if you had a stroke caused by a blood clot that came from the heart. If a PFO doesn't cause problems, then you probably won't need treatment.