What Is Patent Foramen Ovale ?
When you talk of a hole in a heart, it would seem that there is a problem. What many people don’t realize is that more than a quarter of our population tend to have one, and in most cases, it does not cause health complications. In fact, most of those with a hole don’t even know about it.
The heart has two holes namely patent foramen ovale (PFO) and atrial septal defect (ASD). These holes are found in your septum between the left and right upper chambers of your heart (atria).
However their causes are different. Atrial septal defect (ASD) is as a result of your septum tissue failure to form properly between the right upper chambers of your heart. ASD is considered congenital, which means a person is born with. 2
Foramen ovale is a hole found in the wall between the left and right chambers of the human fetus. The hole is used during fetal circulation to quicken flow of blood through the heart.
The baby in the womb depends on the mother to provide blood and oxygen from the placenta via the umbilical cord to the fetus. Foramen ovale allows blood to circulate in the baby’s heart without moving through the baby’s lungs.
Patent Foramen Ovale
When a child is born and breathes for the first time, the foramen ovale shuts and seals completely. If the foramen ovale remains open or fails to close properly, this is referred to as patent foramen ovale (PFO).
Patent foramen ovale affects less than 25% of the general population, globally. Young adults below the age of 55 who have cryptogenic stroke (unknown stroke) are more vulnerable to patent foramen ovale.
If blood flowing through right and left chambers of the heart has a blood clot, it can pass through patent foramen ovale into the left atrium and travels to the coronary artery or brain. This can lead to stroke or heart attack.
Patent foramen ovale is usually a hidden condition and many people who have it do not show any symptoms. However, complications may arise from a case of PFO since blood is crossing from right atrium to the left atrium.
When PFO refuses to close after birth, it creates a movable flap on the wall between the atria. If there happens to be differences in pressure in the atria (pressure in right atrium is more than that in left atrium) it may result in blood leaking from right atrium to enter the left atrium.
In this case, the blood does not go through the lungs for filtration and to carry new oxygen. It follows a fetal-like circulation.
The deoxygenated blood that is moving back to the body without being filtered tends to have bloodborne substances like air, thrombi, and vasoactive substances. These things can cause cerebrovascular problems. That’s why PFOs are sometimes associated with symptoms such as migraine, stroke, decompression illness, or arterial embolism.
It is not clear what causes foramen ovale to remain open in some people. The condition is thought to be connected to genetic factors. However, people with cryptogenic stroke are more likely to have patent foramen ovale.
It is very difficult to find out if a person has Patent foramen ovale (PFO) condition. This condition is not investigated unless a person shows severe symptoms of migraine and stroke. Migraine are severe headaches that can occur during childhood or adulthood. Some of the severe symptoms of migraine include:
- You feel very weak on one side of your body which can lead to paralysis.
- You are unable to maintain balance and coordinate properly.
- You feel severe and painful pulsating on one side of your head.
- You can experience loss in vision or changes in vision.
Your cardiologist can conduct the following tests to diagnose you or child with Patent foramen ovale (PFO):
This type of test uses very high sound waves sent from the transducer to your heart. The transducer will collect sound waves echoes as they bounce off from different parts of your heart. These echoes are then transformed into motion pictures of the heart that can be displayed and watched as a video on a screen. There are different types of echocardiogram tests that be conducted such as:
This type of echocardiogram involves moving the transducer on different parts of your chest and abdomen to view the heart. It is done to check for unusual heart sounds, congenital heart defects, irregular heartbeats, enlarged heart, heart valves, blood clots and diseases.
This type of echocardiogram test is done before and after your heart is strained through exercises or injecting medicines.
Exercises and medicines make your heart palpitate faster and harder. This test is carried out to determine if you have a coronary artery disease. Coronary artery disease occurs when fat builds up in your artery hence prevents blood from flowing to your heart.
Doppler echocardiogram test checks the flow of blood through your heart chambers, blood vessels and heart valves. As blood moves it reflects sound waves to the transducer. Your cardiologist uses an ultrasound computer to measure the direction and speed of blood moving through your blood vessel and heart.
In this test, your cardiologist inserts the probe through your esophagus after applying an anesthetic to your throat to make you comfortable. This test is done to monitor the function of your heart during surgery, identify unusual blood movement in the heart and look if your aorta is torn.
PFOs are not considered to be threatening, but they may be associated with conditions like migraine and stroke. Many people with patent foramen ovale (PFO) require no treatment. However, your doctor can recommend surgery to close your foramen ovale or prescribe medications to prevent stroke.
Prevention of Stroke
Blood clots can pass through your foramen ovale into the brain and cause stroke. This is why your doctor will prescribe the following medication to help prevent the risks associated with blood clots crossing your foramen ovale:
- Blood thinners such as apixaban, rivaroxaban
Cardiac catheterization is a procedure where a catheter is gradually inserted in your heart.
In this procedure, your doctor makes a small cut in your inner thigh (groin region) and inserts a catheter into your large vein and pushes it into the heart. Your doctor will conduct other tests to measure the patent foramen ovale and determine if there are other defects. These tests include:
- The doctor will conduct an angiography test, which is a form of X- ray procedure used to determine the health of your blood vessels and how blood move through them. Since blood vessels do not show well on a normal X-ray, your doctor injects a dye in your blood to allow the doctor see clearly your heart.
- Another ultrasound imaging procedure called intracardiac echo (ICE) is done to see clearly the defect and determine the size of the closure device needed. This intracardiac echo (ICE) is pushed further into your heart through the vein and your doctor places a closure device to the right place of the heart to close a patent foramen ovale. The device is placed there permanently to stop unusual flow of blood between your two artrial chambers of the heart. The catheter will be removed once the procedure is complete.
- Patent Foramen Ovale. Available at http://www2.isu.edu/radsci/papers/110.pdf
- Patent Foramen Ovale (PFO). Available at http://www.heart.org/HEARTORG/Conditions/More/CardiovascularConditionsofChildhood/Patent-Foramen-Ovale-PFO_UCM_469590_Article.jsp#.WONqvNnbs2w
- Closing a Patent Foramen Ovale, Catheter-Based Procedures, and PFO Closure Devices. Available at http://my.clevelandclinic.org/health/articles/how-is-a-patent-foramen-ovale-pfo-closed-using-catheter-based-procedure
- Angiography. Available at http://www.nhs.uk/conditions/angiography/Pages/Introduction.aspx
- Echocardiogram. Available at http://www.webmd.com/heart-disease/echocardiogram#1
- Patent Foramen Ovale Treatment & Management. Available at http://emedicine.medscape.com/article/156863-treatment
- Patent Foramen Ovale repair. Available at https://www.urmc.rochester.edu/cardiology/patient-care/treatments-procedures/pfo_repair.aspx