Patent Ductus Arteriosus (PDA) Complications Clinical features and Diagnosis

  • The ductus normally closes at birth.
  • When the ductus remains patent then a left-to-right shunt exists between the aorta to the pulmonary ar­ery. The ductus is attached to the aorta just after he origin of the left subclavian artery.
  • he ductus is attached to the pulmonary artery just close to its bifurcation or to the left pulmonary artery just at its origin from the pulmonary artery.
  • normally aortic pressure is 56 times that in the pul­monary artery so that flow across the ductus is from the aorta to the pulmonary artery i.e. left-to-ri ht. When the pulmonary artery pressure and resistance increase gradually then a time comes when the flow is reversed i.e. from the pulmonary artery to the aorta i.e. right-to-Ieft. then PDA occurs due to maternal rubella in the other during pregnancy then other features of this
  • syndrome may also be seen like microcephaly, cata­ct, deafness.
Patent Ductus Arteriosus (PDA)

Patent Ductus Arteriosus (PDA) Complications Clinical features and Diagnosis

Complications of Patent Ductus Arteriosus (PDA)

  • Impairment of growth and nutrition
  • Pulmonary hypertension
  • Infective endocarditis V Congestive heart failure
  • Recurrent respiratory infections ~ Aneurysm of the pulmonary artery

Clinical features and Diagnosis of Patent Ductus Arteriosus (PDA)

  •  Female: male ratio 3 : 1
  • The pulse pressure is widened
  • The peripheral pulse is of high volume.
  • There may be differential cyanosis i.e. cyanosis 9nd clubbing of the lower extremities only.
  • There is hyperdynamic apical impulse
  • There may be left ventricular hypertrophy
  • There is reversed splitting of S2
  •  S3 may be present
  •  An aortic systolic ejection sound may be heard at the base of the heart.
  • There is a continuous murmur with thrill best heard in the 2ndleft intercostal space radiating to beneath the left clavicle.
  • It may well be heard all over the precordiut!1.
  • The murmur starts with systole and engulfs the second sound with late systolic accentuation and extends to mid or late diastole.
  • When pulmonary hypertension occurs, the dias­tolic component disappears and later the sys­tolic component also shortens and finally there Tay be no murmur at all.
  • In the newborn, aortic systolic pressure is greater than pulmonary systolic pressure, but this gradient may not be present during diastole
  • flow murmur i.e. a mid-diastolic rumbling murmur at the apex is present.PDAs can be categorized by the degree of left-to-right shunting based upon the pulmonary to systemic flow ratio (Qp:Qs)
    • Small — Qp:Qs <1.5 to 1
    • Moderate — Qp:Qs between 1.5 and 2.2 to 1
    • Large — Qp:Qs >2.2 to 1


  • patients with a large PDA, these features become more pronounced with enlargement,
  • · Left ventricular hypertrophy
  • · Left atrial enlargement
  • · Right ventricular hypertrophy
  • findings on chest radiography vary with the size of the ductus and the degree of left-to-right shunting


  • large PDA with a large left-to-right shunt typically produces ECG findings of biventricular hypertrophy and a left atrial abnormality
  • Left ventricular hypertrophy
  • Left atrial enlargement
  • Left axis deviation Biventricular hypertrophy

2D echocardiography and Doppler flow

  • In the high parasternal short axis view the ductus can be seen arising from the anterior aspect of the descending aorta,
  • · The ductus can be seen and the pulmonary pres­sures estimated.
  • · Associated lesions and complications can be seen.

Patent Ductus Arteriosus (PDA) Treatment

  • Elective closure of the ductus as early as pos­sible.
  • It cannot be done after the reversal of flow across the ductus i.e. when Eisenmenger syndrome develops.


One of the 1st in India.High Quality Generic Medicine Portal Android Application for Online Oreder & Information.

For More Join Our Membership and Get Additional 25% off on Meds, also get MLM Benefits to get a permanent earning source.

Join Membership How to Search Medicine
Android App

We would like to keep you updated with special notifications.