Patent Foramen Ovale. An Unfamiliar Hidden Congenital Condition
When discussing about heart disease, many probably think about coronary artery disease, heart failure or cardiac arrhythmia, and perhaps only a few people have thought about patent foramen ovale that is caused by the foramen ovale’s failure to close. In reality, statistics show that up to 25 percent of the population has this disease, most of whom are asymptomatic. As a result, patients do not know that they already have this abnormality. So, what is patent foramen ovale? How does it affect the body? Let’s learn about this abnormality!
What is Patent Foramen Ovale?
Patent foramen ovale or PFO is the term used to describe a condition of where the wall separating the two upper heart chambers or the foramen ovale is not closed. It is when there is a small open or leak in the wall between the left and right atria. This is a congenital abnormality, since in a majority cases, the foramen ovale is physiologically fully closed within 3 months after child birth. If it never closes fully, then a leak can occur and lead to impacts and problems at any time.
How is the foramen ovale opening related to a fetus’s circulatory system during pregnancy?
Normally, the human body has the vena cava or a vein that functions to receive deoxygenated blood from different parts of the body into the heart to transfer it to the lungs. The blood transported by the inferior vena cava enters the right atrium and then through an opening in the foramen ovale to directly enter the left atrium without having to go through the right ventricle or pulmonary circulation, which happens after a baby is born and allows highly oxygenated blood to enter the left ventricle and then the aorta to be supplied to major organs like the heart and brain.
Do you know that a fetus’s circulatory system is different from an adult’s?
In addition to blood flowing through the foramen ovale, blood from the superior vena cava passes through the right ventricle to enter the pulmonary arteries to reach the lungs. However, because the lungs of a fetus are not yet functional, blood cannot flow into it. Instead, blood from the pulmonary arteries flow into the aorta through a small artery known as ductus arteriosus. The fact that fetuses have the ductus arteriosus and foramen ovale that cause blood from the left and right ventricles to flow in parallel is different from adults, which have a more complete circulatory system.
Why does the foramen ovale close after birth?
Once an infant starts breathing, the lungs expand along with the blood vessels in the lungs, thereby leading to reduced pressure in the lungs. From being unable to flow into the lungs before, more blood begins to flow into the lungs and back to the left atrium of the heart, leading pressure in the left atrium to be greater than the right atrium (In fetuses, the pressure is higher in the right chamber.) and for the foramen ovale to close.
What happens if the foramen ovale does not close?
Because the heart receives deoxygenated blood via the right atrium in order to transport it for oxygenation in the lungs, if the foramen ovale does not fully close, some deoxygenated blood can flow back into the left atrium before going through the carotid arteries to our brain, thus potentially leading to carotid stenosis.
If anyone has frequent chronic headaches or carotid stenosis without a known cause, it is important to consult a medical professional. This is because patent foramen ovale can be detected only if the patient undergoes testing to specifically screen for this condition!
You may find our specialist at our Heart Center
Phyathai 2 Hospital
International Correspondence Center
Tel: +66-2617-2444 ext. 2020 or 2047 E mail: onestop@phyathai.com
@pt2_inter
Phyathai 2 Cambodia
PT2Chinese
phyathai2inter
