What Is Patent Ductus Arteriosus?
Patent ductus arteriosus (PDA) is a fairly common congenital heart defect that occurs in about 3,000 newborns every year in the United States, according to the Cleveland Clinic. It occurs when a temporary blood vessel, called the ductus arteriosus, doesn’t close soon after birth. Symptoms may be minimal or severe. In rare cases, the defect can go undetected and can exist in adulthood. Correction of the defect is usually successful and restores the heart to its normal function.
In a normally functioning heart, the pulmonary artery carries blood to the lungs to collect oxygen. The oxygenated blood then travels through the aorta (the body’s main artery) to the rest of the body. In the womb, a blood vessel called the ductus arteriosus connects the aorta and pulmonary artery. It allows blood to flow from the pulmonary artery to the aorta and out to the body without going through the lungs. This is because the developing child gets oxygenated blood from the mother, not from their own lungs.
Soon after a baby is born, the ductus arteriosus should close up to prevent mixing oxygen-poor blood from the pulmonary artery with oxygen-rich blood from the aorta. When this doesn’t happen, the baby has patent ductus arteriosus (PDA). If a doctor never detects the defect, the baby may grow into an adult with PDA, although this is rare.
PDA is a fairly common congenital heart defect in the United States, but doctors aren’t sure exactly what causes the condition. Premature birth can put babies at risk. PDA is more common in girls than boys.
The opening in the ductus arteriosus can range from small to large. This means that symptoms may be very mild to severe. If the opening is very small, there may be no symptoms and your doctor may only find the condition by hearing a heart murmur.
Most commonly, an infant or child with PDA will have the following symptoms:
- rapid and heavy breathing
- poor weight gain
- little interest in feeding
In the rare case that PDA goes undetected, an adult with the defect may experience symptoms that include heart palpitations, shortness of breath, and complications such as high blood pressure in the lungs, an enlarged heart, or congestive heart failure.
A doctor will usually diagnose PDA after listening to your child’s heart. Most cases of PDA cause a heart murmur (an extra or unusual sound in the heartbeat), which a doctor can hear through a stethoscope. A chest X-ray may also be necessary to see the condition of a baby’s heart and lungs.
Premature babies may not have the same symptoms as full-term births, and may require additional tests to confirm PDA.
An echocardiogram is a test that uses sound waves to create a picture of the baby’s heart. It’s painless and allows the doctor to see the size of the heart. It also lets the doctor see if there’s any abnormality in blood flow. Echocardiogram is the most common method to diagnose PDA.
An EKG records the electrical activity of the heart and detects irregular heart rhythms. In babies, this test can also identify an enlarged heart.
In cases where the opening of the ductus arteriosus is very small, no treatment may be necessary. The opening can close as an infant gets older. In this case, your doctor will want to monitor the PDA as the baby grows. If it doesn’t close on its own, medication or surgical treatment will be necessary to avoid complications.
In a premature baby, a drug called indomethacin can help close the opening in PDA. When given intravenously, this medication can help constrict muscles and close off the ductus arteriosus. This type of treatment is typically only effective in newborns. In older infants and children, further treatment may be necessary.
In an infant or child with a small PDA, your doctor may recommend a “trascatheter device closure” procedure, according to the National Heart, Lung, and Blood Institute. This procedure is done as an outpatient and does not involve opening the child’s chest. A catheter is a thin flexible tube that is guided through a blood vessel starting in the groin and is guided to your child’s heart. A blocking device is passed through the catheter and placed in the PDA. The device blocks the blood flow through the vessel and allows normal blood flow to return.
If the opening is large or it doesn’t seal on its own, surgery may be necessary to correct the defect. This type of treatment is typically only for children who are six months or older. However, younger infants can have this treatment if they have symptoms. For surgical procedures, your doctor may prescribe antibiotics to prevent bacterial infection after leaving the hospital.
Most cases of PDA are diagnosed and treated soon after birth. It’s very unusual for PDA to go undetected into adulthood. If it does, however, it can cause several health problems. The larger the opening is, the worse the complications. However rare, untreated adult PDA can lead to other medical conditions in adults, such as:
- shortness of breath or heart palpitations
- pulmonary hypertension, or raised blood pressure in the lungs, which can damage the lungs
- endocarditis, or inflammation of the lining of the heart due to a bacterial infection (people with structural heart defects are at a higher risk of infection)
In very serious cases of untreated adult PDA, extra blood flow can eventually increase the size of the heart, weakening the muscle and its ability to pump blood effectively. This can lead to congestive heart failure and death.
The outlook is very good when PDA is detected and treated. Recovery for premature babies will depend on how early the baby was born and whether or not other illnesses are present. Most infants will make a complete recovery without experiencing any PDA-related complications.