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 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.