Patent foramen ovale

Alternative names


Fetuses have a normal opening between the left and right atria (upper chambers) of the heart. If this opening fails to close naturally soon after the baby is born, the condition is called patent foramen ovale (PFO).

Causes, incidence, and risk factors

PFO is the persistence of a fetal opening between the left and right atria (upper chambers) of the heart. This hole allows blood to bypass the lungs, because they are not used until a baby is born. The foramen ovale normally closes soon after the infant is born.

The foramen ovale may remain open in as many as 1 out of 5 people. The cause is unknown and there are no known risk factors for developing a PFO.

Infants with a patent foramen ovale and no other heart defects do not have symptoms.

Signs and tests
The only sign (which occurs only rarely) of a PFO is intermittent bluish discoloration of the baby’s skin (cyanosis). This usually occurs during crying or straining to pass stool.

This condition is not treated unless other heart abnormalities exist.

Expectations (prognosis)
The infant will have normal health in the absence of other heart defects.


Unless there are other associated defects, there are usually no complications associated with PFO. There have been some studies suggesting that older patients with PFOs have a higher rate of a certain type of Stroke (thromboembolic). The reason for this is that older people frequently develop Blood clots in the veins in their legs. These clots can sometimes travel from their original site to the right side of their heart.

If PFO is present, the clot can then pass from the right side to the left side from whence it can travel to the brain and become lodged there, preventing blood flow to that part of the brain (Stroke).

Calling your health care provider
Call your health care provider if your baby turns blue when crying or defecating. Usually, however, this disorder is only discovered incidentally when a cardiologist performs an echocardiogram (ultrasound of the heart) to evaluate an unrelated Heart Murmur.

Johns Hopkins patient information

Last revised: December 2, 2012
by Arthur A. Poghosian, M.D.

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