What is a Patent Foramen Ovale?

Patent foramen ovale refers to an opening in the heart that forms during the development of a fetus. This opening should close on its own after birth, but it may remain open in some individuals. Many adults with patent foramen ovale have no symptoms and the opening may be discovered during routine testing.

During fetal development, blood from the mother circulates through the umbilical cord and into the fetus. This blood is oxygen rich and first enters the right atrium of the fetal heart. Since the lungs of the fetus are collapsed, blood does not travel into the lungs to absorb oxygen. Instead, fetal blood bypasses the lungs and flows from the right atrium to the left atrium through a small hole called the patent foramen ovale.

At the time of birth, the fetal lungs expand and begin to supply oxygen to the baby. At this time, the pressure inside the left atrium of the heart increases. This pressure forces a flap of tissue over the patent foramen ovale to close. Within a year after birth, the opening has fused and become part of the wall between the left and right atrium.

If the opening does not close, blood can leak back and forth between the atriums. In many patients, this leakage does not cause any symptoms. However, the presence of patent foramen ovale has been linked to strokes, migraines, and decompression sickness. Patients are often diagnosed with this condition during testing for other heart problems.

Diagnosis is most often made during an echocardiogram, which is an ultrasound of the heart. The opening in the heart and blood leakage can be seen during this test. Many patients do not have any symptoms and may not need treatment. Patients with other heart conditions or who are at risk of having a stroke may need to have the patent foramen ovale closed.

Closure of this hole between the atriums is most often done in a cardiac catheterization facility. A catheter can be inserted into the femoral vein in the groin area and threaded up to the heart. Small devices made of two discs held together by a small rod are available that can then be routed through the catheter and inserted into the atrium. The device is placed over the opening in the heart and opened to cover the patent foramen ovale. This device remains in place and should stop any leakage of blood between the chambers.