Patent ductus arteriosus

(Redirected from PDA)


  • Ductus arteriosus is a blood vessel connecting main pulmonary artery to proximal descending aorta
    • Shunts blood from right ventricle to bypass fetus's non-functioning lungs in utero
  • In PDA, ductus fails to close after birth
  • Second most common congenital heart disease
  • Approximately 1 in 1600 to 5000 live births in the US.[1]


  • Ductus arteriosus shunts blood from the pulmonary artery to the aorta bypassing the lungs while in utero
  • Normally closes soon after birth via complex process
    • Regulated by oxygen tension and decreases in prostaglandin E2
    • Becomes ligamentum arteriosum
  • In PDA, ductus fails to close
    • Results in shunting of blood between aorta and pulmonary artery
    • Some oxygenated blood from high-pressure aorta shunts to lower pressure pulmonary artery
    • A large shunt can cause increased fluid return to lungs and increased lung pressure, leading to pulmonary hypertension
  • Some congenital heart defects, such as transposition of the great arteries, are incompatible with life 'without a PDA; may be necessary to allow oxygenated and deoxygenated blood to mix
    • In these cases prostaglandins are used to keep the ductus arteriosus open.

Clinical Features

Differential Diagnosis

Congenital Heart Disease Types


Echocardiography demonstrating PDA[3]
  • Careful physical examination demonstrating characteristic machine like murmur
  • Echocardiography
    • MRA and Cardiac CT can also be used as diagnostic tools
  • Laboratory tests usually not helpful


  • Spontaneous closure common
  • If significant respiratory distress or impaired oxygen delivery, therapy usually required

Medical Therapy

  • IV indomethacin: usually effective when administered in the first 10-14 days of life.
    • <48 hour old: start 0.2mg/kg IV x 1, then 0.1mg/kg q12-24h x 2
    • 2-7 days old: Start 0.2mg/kg IV x 1, then 0.2mg/kg q12-24h x 2
    • > 7 days old: Start 0.2mg/kg IV x 1, then 0.25mg/kg q12-24h x 2

Surgical Therapy

  • Offered if medical therapy fails
    • Cardiac catheterization and catheter closure
    • Surgical ligation


  • Stable, asymptomatic patients can be discharged home with cardiology follow-up
  • Symptomatic patients and patients requiring treatment should be admitted with cardiology consultation

See Also

External Links


  1. Mitchell, S. C., Korones, S. B., Berendes, H. W. Congenital heart disease in 56,109 births: incidence and natural history. Circulation 43: 323-332, 1971.
  2. Knipe K et al. Cyanotic congenital heart diseases. Radiopaedia.