Patent Ductus Arteriosus

What is patent ductus arteriosus?

Patent ductus arteriosus (often shortened to PDA) is a heart condition in which a small blood vessel that every baby has before birth fails to close after birth. The word patent simply means “open,” and the ductus arteriosus is the name of that vessel. Before birth, the ductus arteriosus connects the two large arteries leaving the heart: the aorta, which carries blood to the body, and the pulmonary artery, which carries blood to the lungs. A baby in the womb does not breathe air, so most blood bypasses the lungs through this vessel. In the first hours to days after birth, the ductus normally tightens and closes on its own. When it stays open, extra blood flows from the aorta into the pulmonary artery and on to the lungs, which can make the heart and lungs work harder than they should.

Patent ductus arteriosus is one of the more common heart conditions present at birth (congenital heart conditions). It is seen most often in babies born prematurely, and it is more likely the earlier a baby is born. It can also occur in full-term babies, and a small opening is sometimes discovered later in childhood or even adulthood. Many small PDAs cause no problems and may close on their own, while larger ones usually need treatment. In a hospital setting, care is typically shared between newborn specialists, pediatric heart specialists, and, for older patients, a Cardiology Department.

Symptoms of patent ductus arteriosus

Patent ductus arteriosus symptoms depend mainly on how large the opening is, how much extra blood is reaching the lungs, and the age of the person. A very small PDA often causes no symptoms at all and may be found only because a doctor hears an unusual heart sound (a murmur) during a routine check. A larger PDA can cause signs of the heart working too hard, which may appear in the first weeks of life.

Common signs and symptoms in babies and young children may include:

• Fast breathing or breathlessness, sometimes with a visible pulling-in of the skin between the ribs
• Tiring easily or sweating during feeds
• Poor feeding and slow weight gain
• A fast heartbeat or a bounding (unusually strong) pulse
• Frequent chest infections or lingering coughs
• A heart murmur heard by a doctor, often described as a continuous “machinery” sound

In premature babies, the picture can be different. These infants may already need help with breathing, and a PDA can make it harder to reduce that support. Doctors caring for premature babies watch closely for signs that a PDA is affecting the lungs, blood pressure, or kidneys.

In older children and adults with an undetected PDA, symptoms may be subtle or absent for years. Some people notice shortness of breath with exercise, palpitations (an awareness of the heartbeat), or reduced stamina. Over a long period, a large untreated PDA can raise the pressure in the lung arteries (pulmonary hypertension), and in rare advanced cases this can cause bluish coloring of the lips or fingertips. This is why an open ductus found later in life is usually evaluated even when the person feels well.

Causes and risk factors

Patent ductus arteriosus causes are not fully understood. In most cases there is no single identifiable reason, and parents have not done anything to cause it. Doctors do know that the ductus closes in response to the changes that happen at birth: the baby starts breathing, oxygen levels in the blood rise, and levels of certain natural chemicals (prostaglandins) that keep the vessel open fall. When these signals are weaker or the vessel is not yet mature enough to respond, the ductus may stay open.

Factors that are known to increase the risk include:

• Premature birth. This is the most important risk factor. The earlier a baby is born and the lower the birth weight, the higher the chance that the ductus remains open, because the vessel and the baby’s lungs are less developed.
• Breathing problems at birth. Conditions that lower oxygen levels, such as respiratory distress syndrome in premature infants, may delay closure.
• Family history and genetic conditions. PDA is somewhat more common when a close relative had a congenital heart condition, and it is seen more often in certain genetic syndromes, including Down syndrome.
• Infections during pregnancy. Rubella (German measles) infection in early pregnancy is a recognized risk factor for several heart defects, including PDA. Routine vaccination has made this uncommon in many places.
• Birth at high altitude. Lower oxygen levels at high altitude appear to be associated with a higher rate of PDA.
• Sex. PDA is reported more often in girls than in boys.
• Other congenital heart conditions. A PDA sometimes occurs together with other structural heart problems, and in some of these the open ductus is temporarily helpful and is deliberately kept open with medication until surgery can be planned.

Diagnosis

Patent ductus arteriosus diagnosis usually begins with a physical examination. A doctor listening to the chest with a stethoscope may hear a characteristic murmur caused by blood flowing continuously through the open vessel. The doctor may also notice a strong, bounding pulse or a wide gap between the upper and lower blood pressure numbers. In premature babies in intensive care, doctors may suspect a PDA from breathing patterns, oxygen needs, or blood pressure readings even before a murmur is heard.

To confirm the diagnosis and understand how much the PDA matters, doctors commonly use the following tests:

• Echocardiogram. This ultrasound scan of the heart is the main test. It is painless, uses no radiation, and can show the open ductus directly, measure its size, and show the direction and amount of blood flowing through it. It also shows whether the heart chambers are enlarged and helps estimate pressures in the lungs. Doppler imaging, a part of the echocardiogram, tracks blood flow in color.
• Chest X-ray. This may show an enlarged heart or extra blood flow to the lungs, although it cannot show the ductus itself.
• Electrocardiogram (ECG or EKG). This records the heart’s electrical activity and may show strain on the heart chambers in larger PDAs. It is often normal when the PDA is small.
• Pulse oximetry. A small sensor on the skin measures oxygen levels. Newborn screening with this device can raise suspicion of some heart conditions, although it does not detect all PDAs.
• Cardiac catheterization. In this procedure a thin tube is passed through a blood vessel into the heart. It is not usually needed to diagnose a PDA, but it may be used in older children or adults to measure lung pressures precisely, and it is often the setting in which a PDA is closed.
• Cardiac MRI or CT scan. These are occasionally used in adults when ultrasound images are not clear enough or when other vessel problems need to be excluded.

Doctors generally describe a PDA as small, moderate, or large based on its size and its effect on the heart. A PDA is sometimes called “hemodynamically significant” when it is clearly causing extra strain on the heart or lungs; this description guides treatment decisions, particularly in premature infants.

Treatment options for patent ductus arteriosus

Patent ductus arteriosus treatment depends on the size of the opening, the symptoms it causes, the age and overall health of the patient, and whether the ductus is likely to close on its own. There is no single approach that fits everyone, and the plan is usually made by a team that may include newborn specialists and heart specialists.

Observation and monitoring. Many small PDAs, especially in otherwise healthy babies, close on their own during the first weeks or months of life. In these cases doctors may recommend regular check-ups and repeat echocardiograms rather than immediate treatment. In premature babies, doctors weigh the risks and benefits of treating versus waiting, and practice varies between centers. Supportive care, such as careful fluid management and breathing support, is often part of this approach.

Medication. In premature infants, medicines that reduce prostaglandin levels can encourage the ductus to close. The medicines most often used are ibuprofen and indomethacin, given by mouth or into a vein; acetaminophen (paracetamol) is also used in some centers. These medicines work best in the first days to weeks of life and are much less effective in full-term babies, older children, and adults. They are not suitable for everyone, because they can affect the kidneys, the gut, and bleeding, so doctors monitor closely during treatment. Sometimes a second course is given if the first does not close the ductus.

Catheter closure. For infants who are beyond the newborn period, older children, and adults, the most common way to close a PDA is a catheter procedure. A thin tube is passed through a blood vessel, usually in the groin, up to the heart, and a small device such as a coil or a plug is placed in the ductus to block blood flow. Over time the body’s own tissue grows over the device. This is done under sedation or general anesthesia, usually does not require opening the chest, and many patients go home the same day or the next day. Devices designed for very small premature babies are now used in some centers.

Surgical closure. Surgery involves an operation through a small cut on the side of the chest to tie off or clip the ductus. It is generally reserved for situations where catheter closure is not possible or not appropriate, for example in some very small premature babies, when the ductus is unusually shaped, or when other heart repairs are needed at the same time. It is a well-established operation with a long track record.

Treatment of complications. If a PDA has already caused heart strain, doctors may use medicines that help the heart pump more effectively or reduce fluid build-up while closure is arranged. In the rare situation where long-standing high lung pressure has developed, closing the ductus may no longer be safe, and specialist care focuses on managing the lung pressure instead.

Recovery and follow-up. After catheter or surgical closure, most patients have follow-up echocardiograms to confirm the ductus is fully closed and that the heart is recovering. Children can usually return to normal activities within a short period as advised by their care team. Adults may need a longer period of follow-up if the heart chambers were enlarged before treatment.

Living with patent ductus arteriosus and outlook

The outlook for most people with a patent ductus arteriosus is generally good, especially when the opening is small or has been closed successfully. Once a PDA is closed and the heart has recovered, many children grow and develop normally and can take part in ordinary school activities and sports, unless their doctor advises otherwise because of another condition. Long-term restrictions are uncommon after a straightforward closure.

For premature babies, the overall outlook is influenced not only by the PDA but also by the other challenges of being born early, such as lung and feeding problems. A PDA is one part of a bigger picture, and the medical team will usually explain how it fits with the rest of a baby’s care.

Some points that often come up in follow-up care:

• After device or surgical closure, doctors usually ask for at least one follow-up scan to confirm there is no remaining flow through the ductus.
• Antibiotics before dental work to prevent heart infection (endocarditis) are not routinely recommended for most people with a closed PDA, but may be advised for a limited time after a device is placed or if any leak remains. Your doctor can explain what applies in your case.
• Adults whose PDA was found late, or who developed heart enlargement or raised lung pressure, generally need longer-term follow-up with a heart specialist.
• A small PDA that is being watched rather than treated usually needs periodic check-ups so that any change can be picked up early.

Living well with this condition mostly means attending follow-up appointments, keeping copies of heart scan reports for future doctors, and knowing the warning signs that should prompt a review. Most people who have had a PDA closed in childhood do not experience related problems as adults, although no outcome can be guaranteed for any individual.

Frequently asked questions

What are the first patent ductus arteriosus symptoms parents might notice?

In babies, the earliest signs are often related to feeding and breathing: breathing faster than usual, getting sweaty or tired while feeding, taking a long time to finish a bottle, and gaining weight slowly. Some babies show no signs at all and the condition is found only when a doctor hears a murmur. Any of these signs can also have other causes, so they should be discussed with a doctor rather than assumed to be a PDA.

Can patent ductus arteriosus close on its own?

Yes, in many cases. The ductus normally closes within the first few days after birth in full-term babies, and a small opening that persists may still close over the following weeks or months. In premature babies spontaneous closure is also common, though it may take longer. The likelihood of closing on its own is lower the larger the opening and the longer it has stayed open, which is one reason doctors monitor small PDAs with repeat scans.

What causes patent ductus arteriosus in full-term babies?

In full-term babies the cause is often unknown. The ductus may have an unusual structure that does not respond normally to the rise in oxygen after birth, or there may be genetic factors, since PDA runs in some families and is seen with certain syndromes. Infection with rubella during pregnancy and birth at high altitude are recognized associations. In most families, no specific cause is ever identified.

How is patent ductus arteriosus diagnosis confirmed?

An echocardiogram, which is an ultrasound scan of the heart, is the standard way to confirm the diagnosis. It shows the open vessel, its size, and how much blood is flowing through it, and it lets doctors check whether the heart is under strain. A chest X-ray and ECG may add information, and in adults a catheter study or advanced imaging is sometimes needed to measure pressures in the lungs before deciding on treatment.

What is the most common patent ductus arteriosus treatment?

It depends on age. In premature babies, medicines such as ibuprofen or indomethacin are often tried first, alongside careful supportive care. Beyond the newborn period, catheter closure with a small coil or plug is the most commonly used approach because it avoids open surgery. Surgery is used when a catheter procedure is not suitable. Very small PDAs without symptoms are often simply monitored.

Is patent ductus arteriosus dangerous if left untreated?

A small PDA may cause no harm and may never need treatment. A moderate or large PDA that is left untreated can, over time, lead to enlargement of the heart, heart failure, repeated lung infections, and high blood pressure in the lung arteries, which can become irreversible. Because of these risks, doctors usually recommend closing a PDA that is causing measurable strain, even if the person currently feels well.

Can adults have patent ductus arteriosus?

Yes. A PDA that was small or quiet in childhood can go unnoticed into adulthood and be found during an examination or scan done for another reason. Adults may have no symptoms or may notice breathlessness or palpitations. Evaluation usually includes an echocardiogram and sometimes catheterization, and closure is often recommended if the heart is affected and lung pressures allow. Adult cases are typically managed within a cardiology service.

When to see a doctor

If your baby or child has been told they have a patent ductus arteriosus, or if you suspect a heart problem, routine concerns can be raised at scheduled check-ups. Some signs, however, need prompt medical attention. Seek urgent care if a baby or child with a known or suspected PDA develops any of the following:

• Rapid, labored, or noisy breathing, or pauses in breathing
• Bluish or gray color of the lips, tongue, or skin
• Refusal to feed, or becoming exhausted or sweaty with every feed
• Unusual sleepiness, floppiness, or difficulty waking
• A fever together with breathing difficulty or a persistent cough
• Very fast or irregular heartbeat, or fainting
• Swelling of the legs, abdomen, or around the eyes, or a sudden drop in the number of wet diapers

Adults with a PDA should seek medical advice if they notice new or worsening shortness of breath, chest pain, palpitations, fainting, or swelling of the ankles. After a closure procedure, any fever, redness or swelling at the catheter site, or unexpected chest pain should be reported to the treating team. Trust your instincts; if a child looks seriously unwell, emergency assessment is appropriate even if none of the specific signs above is present.