What is a patent ductus arteriosus (PDA)?
A patent ductus arteriosus (PDA) is a heart defect in which a channel that exists between two major blood vessels before birth fails to close as it is supposed to shortly after birth.
Every baby is born with an open connection between the two major blood vessels emerging from the heart, the pulmonary artery and the aorta. The channel is called the ductus arteriosus. The pulmonary artery carries blood from the right pumping chamber of the heart (the right ventricle) to the lungs. The aorta carries blood from the left side of the heart (the left ventricle) to the rest of the body.
Normally, the channel closes within 3 days after birth. When this fails to happen, some of the blood that should have gone through the aorta and on to the rest of the body is returned through the PDA to the lungs. Failure of this channel to close is quite common in premature infants but is fairly rare in full-term babies. Less commonly, it may not be detected until later in life.
How does it occur?
In premature infants, particularly if their lungs are not mature, the PDA often does not close normally. In full-term infants, the cause is unknown.
What are the symptoms?
Babies who have a small open channel often will have no symptoms except a heart murmur. If the PDA is large, the babies may have difficulty gaining weight and become short of breath and sweat when they exert themselves (such as when they cry). Older children may not be able to exercise as much as normal and may have frequent lung infections.
How is it diagnosed?
Most babies with this defect will have a heart murmur, which the health care provider will hear with a stethoscope. Some PDAs are silent, however. An echocardiogram, a special test that uses sound waves to create a picture of the heart, will reveal a PDA. A chest x-ray of a child with a PDA will often show an increased amount of blood in the lungs.
How is it treated?
In premature babies, a PDA often closes by itself within weeks or months. In full-term infants or in premature infants whose PDA fails to close, surgery is needed.
There are three common ways to close a PDA surgically. In the first, the surgeon makes a small cut under the armpit. The ribs will be spread (not broken) and the PDA exposed. The surgeon will then tie off the PDA.
In the second method, two or three small tubes will be inserted in the baby’s side. Small instruments are used to tie off the PDA through these small tubes. This is called thoracoscopic surgery.
The third way of closing the PDA uses tubes that are inserted in a leg artery and pushed through to the PDA. Special coils are then inserted into the PDA that keep blood from flowing into it. This procedure uses a technique known as cardiac catheterization.
Discuss the options with your health care provider before making a treatment decision.
How long do the effects last?
Surgery involves little risk, corrects the problem, and enables the child to grow and develop normally.