---
title: Patent ductus arteriosus
description: What a patent ductus arteriosus is, why it fails to close after birth, how it is found, when and how it is closed and when to see a doctor urgently.
type: disease
aliases:
  - PDA
sources:
  - tier: guideline
    org: minzdrav-rf
    title: Открытый артериальный проток (ОАП)
    year: 2024
    url: https://cr.minzdrav.gov.ru/view-cr/43_2
  - tier: guideline
    org: esc
    title: 2020 ESC Guidelines for the management of adult congenital heart disease
    year: 2020
    doi: 10.1093/eurheartj/ehaa554
    url: https://doi.org/10.1093/eurheartj/ehaa554
  - tier: reference
    org: msd-manuals
    title: Patent Ductus Arteriosus (PDA)
    year: 2023
    url: https://www.msdmanuals.com/professional/pediatrics/congenital-cardiovascular-anomalies/patent-ductus-arteriosus-pda
sources_checked: 2026-10-12
review: null
---

The ductus arteriosus is a blood vessel that connects the <Structure id="aorta">aorta</Structure> and the <Structure id="pulmonary-trunk">pulmonary artery</Structure>. A baby needs it before birth, and it should close after birth; a patent ductus arteriosus (PDA) is a duct that stays open after birth.<Cite n={[1, 3]} /> The duct usually leaves the arch of the aorta opposite the left subclavian artery and joins the pulmonary artery where the left pulmonary artery begins.<Cite n={[1, 2]} />

In babies born at term the duct closes in two stages: in the first 10–15 hours after birth its wall contracts and it narrows, and then, usually over 2–3 weeks, it scars over and turns into a firm cord, the ligamentum arteriosum.<Cite n={1} /> If the duct has not closed within the first 3 months of life, it is called a persistent patent duct.<Cite n={1} />

<Diagram name="patent-ductus-arteriosus">
  <p slot="normal">
    Normally the duct closes after birth and becomes the ligamentum arteriosum, so the aorta and
    the pulmonary artery are no longer connected.<Cite n={[1, 3]} />
  </p>
  <p slot="disease">
    With a patent duct, some of the blood from the aorta flows through it into the pulmonary
    artery. As a result, the lungs receive more blood than they should.<Cite n={[1, 3]} />
  </p>
  <p slot="treated">
    After the procedure the duct is closed: through a catheter it is blocked with an occluder or
    coils, and in surgery it is tied off, divided and sewn, or closed with a clip.<Cite n={[1, 3]} />
    The doctor chooses the closure method. Blood no longer flows through the duct from the aorta into
    the pulmonary artery, although in rare cases a residual shunt remains after closure.<Cite
      n={[1, 2, 3]}
    />
  </p>
</Diagram>

## Why it happens

<Patient>

Before birth a baby does not breathe: it gets oxygen from the mother. The duct lets blood bypass the lungs and go straight into the aorta.<Cite n={1} /> With the first breath, blood starts flowing into the lungs and the duct is no longer needed.<Cite n={1} /> It is narrowed by the oxygen in the blood and by a fall in prostaglandins, substances that keep the duct open.<Cite n={[1, 3]} />

If the duct does not close, blood flows through it the other way: from the aorta into the blood vessels of the lungs.<Cite n={1} /> The lungs receive extra blood, and the left side of the heart has to pump a larger volume.<Cite n={[2, 3]} /> The duct most often stays open in babies born prematurely: the lower the birth weight, the more often this happens.<Cite n={[1, 3]} /> PDA is about three times more common in girls than in boys.<Cite n={[1, 3]} />

</Patient>

<Student>

In the fetus, blood flows through the duct from right to left, from the pulmonary artery (PA) into the aorta, because pulmonary vascular resistance is high and placental resistance is low; after the first breath, pressure in the pulmonary vessels falls and the shunt becomes left-to-right.<Cite n={1} /> Postnatal closure has two stages: functional (contraction of the smooth muscle of the media and apposition of the intimal cushions) and anatomical, with intimal fibrosis forming the ligamentum arteriosum.<Cite n={1} /> A rise in PO2 constricts the duct, while prostaglandins (PGE1, PGE2, prostacyclin) relax it; the immature duct is more sensitive to prostaglandins, so prolonged patency is more common in preterm infants.<Cite n={1} />

According to the Russian Ministry of Health guideline, PDA accounts for 7% of all congenital heart defects; according to MSD, 5–10%.<Cite n={[1, 3]} />

</Student>

<HeartModel highlight={['aorta', 'pulmonary-trunk']} />

## Symptoms

<Patient>

What happens depends on the size of the duct: anything from no symptoms at all to a very serious illness.<Cite n={[1, 3]} /> A small duct usually causes no problems in childhood and is found when a doctor hears a heart murmur.<Cite n={[1, 3]} /> With a medium-sized duct a child may lag slightly behind in development and may have breathlessness, tiredness and frequent lung infections, but many feel well for years.<Cite n={1} />

A large duct shows itself in the first weeks of life with signs of heart failure: the baby breathes fast, has a fast heartbeat, sweats, is irritable, feeds poorly and gains weight slowly.<Cite n={[1, 3]} /> Premature babies may have breathing problems and other serious complications, such as necrotising enterocolitis, a severe disease of the bowel; in them heart failure starts earlier and may be more severe.<Cite n={3} />

If a large duct is not closed, pulmonary hypertension and Eisenmenger syndrome, irreversible damage to the blood vessels of the lungs, develop over time.<Cite n={[1, 3]} />

</Patient>

<Student>

The characteristic signs are a continuous systolic-diastolic murmur in the 2nd–3rd intercostal space to the left of the sternum and a reduced diastolic blood pressure.<Cite n={1} /> If the continuous murmur is loud, it has a "machinery" quality; according to MSD, term infants with a significant shunt have bounding pulses with a wide pulse pressure.<Cite n={3} /> "Silent" forms occur in 0.5–1% of cases; with severe heart failure the murmur is usually not heard, and it disappears with the development of Eisenmenger syndrome.<Cite n={[1, 2]} />

In adults the ESC distinguishes a small asymptomatic duct, a moderate duct with predominant LV volume overload or with pulmonary hypertension, and a large duct with Eisenmenger physiology and differential cyanosis: the lower extremities are cyanotic, sometimes the left arm too.<Cite n={2} /> Aneurysm formation of the duct is a very rare complication.<Cite n={2} />

</Student>

## How it is diagnosed

<Patient>

A doctor may suspect a patent duct from a heart murmur.<Cite n={[1, 3]} /> The key test is an ultrasound scan of the heart (echocardiogram) with Doppler: it shows the duct itself and the blood flowing through it.<Cite n={[1, 3]} /> An ECG and a chest X-ray are also done; with a small duct they are usually normal.<Cite n={[1, 3]} /> Blood pressure is also measured in the legs so as not to miss a narrowing of the aorta (coarctation) as well.<Cite n={1} />

</Patient>

<Student>

Transthoracic echocardiography with colour Doppler is recommended for all patients with PDA; it assesses the diameter of the duct, the direction and velocity of the shunt and pulmonary hypervolaemia or hypertension, and the size of the left atrium and LV indirectly reflects the size of the shunt.<Cite n={1} /> With a significant shunt, the chest X-ray shows prominence of the left atrium, left ventricle and ascending aorta and increased pulmonary vascular markings, and the ECG shows LV hypertrophy.<Cite n={[1, 3]} /> In adults, oxygen saturation should be measured at the upper and lower extremities.<Cite n={2} />

Cardiac catheterisation is usually not needed for the diagnosis; it is done when there are signs of raised PA pressure, to determine pulmonary vascular resistance and whether the duct can be closed.<Cite n={[1, 2, 3]} />

</Student>

## How it is treated

<Patient>

Doctors choose the treatment according to how early the baby was born and the baby's condition.<Cite n={1} /> In premature babies whose duct disturbs the circulation, a team of doctors may decide to give medicines that block the production of prostaglandins.<Cite n={[1, 3]} /> If a premature baby is breathing normally and has no other problems, the duct is usually not treated: it may close on its own.<Cite n={3} /> In babies born at term and in children older than a month, these medicines usually do not work.<Cite n={[1, 3]} />

There are two ways to close the duct. With a catheter, without an incision: a device, an occluder or a coil, is passed through a blood vessel in the groin to the duct and blocks it.<Cite n={[1, 3]} /> Or with surgery: through a small cut on the side of the chest, or several very small cuts, the duct is tied off or closed with a clip.<Cite n={1} /> If there are no complications, the Russian Ministry of Health guideline considers 6 months to 5 years the best age for the procedure; with complications the duct can be closed earlier.<Cite n={1} /> Closing the duct in good time can lead to a full recovery.<Cite n={[1, 3]} />

According to the Russian Ministry of Health guideline, after the operation a person should see a cardiologist and have a heart ultrasound at least once in the first year, and after that can be followed up by a local cardiologist at least once every two years.<Cite n={1} /> In the first 6 months after closure, the doctor may prescribe prevention of infective endocarditis.<Cite n={[1, 3]} />

</Patient>

<Student>

In infants with heart failure, supportive treatment, including diuretics, is given before the duct is closed to relieve symptoms.<Cite n={[1, 3]} /> Medical closure of a haemodynamically significant duct in preterm infants is based on suppressing prostaglandin synthesis with cyclo-oxygenase (COX) inhibitors (non-steroidal anti-inflammatory drugs).<Cite n={[1, 3]} />

Indications for closure are a haemodynamically significant duct, previous endocarditis or an aneurysm of the duct; according to the ESC, in adults with LV volume overload and no pulmonary arterial hypertension the duct is closed regardless of symptoms.<Cite n={[1, 2]} /> The ESC considers device closure the method of choice in adults; according to the Russian Ministry of Health guideline, transcatheter closure can be performed safely in children weighing more than 6 kg and in adults with a left-to-right shunt.<Cite n={[1, 2]} /> According to the Russian Ministry of Health guideline, surgery is preferred for a large-diameter or short duct, calcification or an aneurysm; in adults the ESC reserves it for the rare duct that is too large for a device or has unsuitable anatomy, such as an aneurysm.<Cite n={[1, 2]} /> Early mortality after surgery is practically nil; possible complications include injury to the laryngeal or phrenic nerve and the thoracic duct, and, with transcatheter closure, displacement of the device.<Cite n={1} /> In Eisenmenger syndrome with a persistent right-to-left shunt, the duct is not closed.<Cite n={[1, 2]} />

According to MSD, endocarditis prophylaxis is needed only for the first 6 months after closure or if there is a residual defect next to the device or surgical material; the ESC limits it in adults to high-risk patients.<Cite n={[2, 3]} />

</Student>

## When to see a doctor urgently

The Russian Ministry of Health guideline lists an aneurysm of the duct and infective endocarditis as reasons for emergency hospital admission in PDA.<Cite n={1} /> The signs of endocarditis are described in the article on [infective endocarditis](../infective-endocarditis/).

If a baby breathes fast, gets breathless when feeding, sweats, feeds poorly and gains weight slowly, do not put off seeing a doctor: these can be signs of heart failure caused by a large duct, and then the duct usually needs to be closed.<Cite n={[1, 3]} />

The site's general safety rule, repeated at the bottom of every page: "If you have chest pain, severe shortness of breath or have fainted, call your local emergency number immediately (112 in the EU, 911 in the US and Canada, 999 in the UK)."

<Quiz />