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.

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 2^ndleft 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

X-ray

• 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

ECG

• 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.