Difference between revisions of "Patent ductus arteriosus"

(Background)
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==Background==
 
==Background==
*Abbreviation: PDA
+
*Ductus arteriosus is a blood vessel connecting main pulmonary artery to proximal descending aorta
*A condition where the ductus arteriosus does not close after birth.  It is the second most common congenital heart disease affecting approximately 1 in 1600 to 5000 live births in the US.<ref>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.</ref>
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**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.<ref>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.</ref>
  
 
===Pathophysiology===
 
===Pathophysiology===
 
[[File:PDA.png|thumb]]
 
[[File:PDA.png|thumb]]
 
*Ductus arteriosus shunts blood from the pulmonary artery to the aorta bypassing the lungs while in utero
 
*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
+
*Normally closes soon after birth via complex process
*In a PDA, the vessel fails to close, resulting in shunting of blood between the aorta and the pulmonary artery
+
**Regulated by oxygen tension and decreases in prostaglandin E2
*This shunting allows some oxygenated blood from the aorta, which has a higher pressure, to the pulmonary artery, which has the lower pressure.
+
**Becomes ligamentum arteriosum
*If the shunt is large enough, can cause increase fluid return to the lungs, increased lung pressure, and thus increased energy demands to fill the lungs.
+
*In PDA, ductus fails to close
*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.
+
**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 [[prostaglandin E1|prostaglandins]] are used to keep the ductus arteriosus '''open'''.
 
**In these cases [[prostaglandin E1|prostaglandins]] are used to keep the ductus arteriosus '''open'''.
  

Revision as of 14:39, 9 March 2019

Background

  • 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]

Pathophysiology

PDA.png
  • 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

  • Continuous machine like heart murmur
  • Differential cyanosis (cyanosis of lower extremities and not the upper extremities)
  • Dyspnea
  • Tachycardia
  • Widened pulse pressure

Differential Diagnosis

Congenital Heart Disease Types

Evaluation

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

Management

  • Spontaneous closure is usually common but if significant respiratory distress or impaired oxygen delivery is present, therapy is usually required.

Medical Therapy

  • IV indomethacin: usually effective when administered in the first 10-14 days of life.

Surgical Therapy:

Cardiac catheterization and catheter closure in addition to surgical ligation are also options if medical therapy fails.

Disposition

See Also

External Links

References

  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. http://radiopaedia.org/articles/cyanotic-congenital-heart-disease
  3. http://www.thepocusatlas.com/pediatrics/