All about open ductus arteriosus

An open ductus arteriosus is a congenital heart defect (present at birth).

An open ductus arteriosus is a persistent opening between the two large blood vessels (the aorta and pulmonary artery) that start from the heart. The pulmonary artery carries blood from the heart to the lungs, where the blood is oxygenated. This oxygen-enriched blood returns to the heart from the lungs. This oxygen-rich blood is supplied from the heart to the body via the aorta.

In the womb, a temporary blood vessel (the ductus arteriosus) forms a normal part of a baby’s circulatory system. The fetus or baby in the womb receives oxygen from the mother’s circulation. Therefore, the fetus ‘heart does not depend on the fetus’ lungs to oxygenate the blood. The ductus arteriosus connects the aorta and the pulmonary artery directly bypassing the lungs, thereby streamlining the fetal circulation. After the birth, the baby’s lungs take over the supply of oxygen to the blood. The body no longer makes chemicals that are needed to keep the ductus arteriosus open. After the birth, the ductus arteriosus usually closes within the first hours or days.

If the ductus arteriosus remains open (patent), it is called the persistent ductus arteriosus or PDA.

How common is an open ductus arteriosus in India?

An open ductus arteriosus is the second most common congenital heart defect after the ventricular septal defect. Studies have shown that more than 80% of epidurals close on their own within eight weeks of birth. Persistent epidurals affect about 1 in 2,500 babies. The incidence of epidurals is more common in girls than in boys (2: 1).

How can an open ductus arteriosus affect my child’s health?

The PDA allows oxygen-rich blood (oxygen-rich blood) in the aorta to mix with deoxygenated blood (deoxygenated blood) in the pulmonary artery. As a result, a higher amount of deoxygenated blood is transported to the lungs via the pulmonary artery, which stresses the heart and increases the blood pressure in the pulmonary arteries.

A small open ductus arteriosus often remains asymptomatic and therefore does not require treatment. However, a large open ductus arteriosus can cause the heart muscle to weaken, leading to heart failure and other complications.

Larger, untreated defects can cause the following complications:

1. High blood pressure in the lungs – Because PDA circulates too much blood through the main arteries of the heart, it can lead to pulmonary hypertension. Pulmonary hypertension can cause permanent lung damage.
2. Heart Failure – A PDA can cause the heart muscles to weaken, which eventually leads to heart failure.
3. Heart infection (endocarditis) – People with open ductus arteriosus are at higher risk of infection or inflammation of the lining of the heart.

What are the most common signs and symptoms of PDA?

Symptoms of an open ductus arteriosus can vary depending on the size of the defect and whether the baby is premature or has completed a full pregnancy. A small defect may not cause symptoms and go undetected until adulthood. A large defect can cause signs and symptoms similar to those of heart failure shortly after birth.

The first sign of a PDA may be a distinct sound (heart murmur), which your doctor may detect during regular tests of the baby’s heart with a stethoscope.

A baby with a large PDA may have the following signs and symptoms:

• Loss of appetite or bad food
• Sweating while eating or crying
• Persistent shortness of breath
• Fatigue and malaise
• Fast heart rate

What are the risk factors that PDA can cause?

Some factors that can increase your risk of PDA include:

1. Premature birth – An open ductus arteriosus is more common in babies born before 37 weeks of gestation than in babies born after a full pregnancy.
2. Family History – Having a family history of heart disease increases the risk of epidurals.
3. Presence of Genetic Disorders – Genetic diseases such as Down syndrome make the baby more likely to have an epidural.
4. Infection – Getting a rubella infection during pregnancy increases your baby’s risk of developing heart defects. This allows the rubella virus to cross the placenta and damage the baby’s blood vessels and important organs.

5. Female Preference – The incidence of open ductus arteriosus is twice as common in women as it is in men.

How is an open ductus arteriosus (PDA) diagnosed?

After detecting a distinct heart murmur with a stethoscope, a doctor may recommend the following tests to confirm the PDA:

• Chest x-ray
• EKG to measure the electrical activity of the heart
• Echocardiogram – An echo shows how big the opening is
• Blood tests

What are the different PDA treatments?

Treatment of the PDA depends on the extent and severity of the defect.

Small defects do not increase the pressure on the heart and lungs and therefore do not justify medical or surgical intervention. They usually close on their own within a few weeks of giving birth.

A PDA can be treated in 3 ways:

1. Medication – For premature babies, cardiologists may prescribe some medications to help close the defect. But after a few weeks, the drugs will not be effective in closing the defect.
2. Catheter-based procedures – A cardiac surgeon inserts a catheter (long thin tube) through the blood vessels in the legs, reaches the heart and the defect, and inserts a coil through that catheter to close the defect.
3. Surgery – Surgery is performed when catheter-based procedures cannot close the defect.

Dr. Arun Bableshwar | Specialist – Cardiology – Pediatrics | SDM Narayana Heart Center, Dharwad