Hi everyone ! Just a short review on Ductus Arteriosus.
- Ductus Arteriosus is basically a communication between the Pulmonary trunk and the Systemic Aorta.
- This communication is between pulmonary trunk and the end of Arch of aorta. Just after the Brachiocephalic trunk , and Left Common carotid and Subclavian have branched off.
- In embryonic life this communication helps transport blood from RV- Pulmonary artery to the Systemic circulation.
So ,
Remember :
Prostaglandins Persist
-Prostaglandins, especially PGE1 , act on the Ductal muscle tissue and keep it Open.
-So the Ductus arteriosus stays open.
-This is important in certain Duct dependent lesions
- Duct dependent heart lesions are those which need the presence of an Open ductus to receive blood in systemic / Pulmonary circulation.
- For example -->
✓ Duct dependent lesions for Systemic Circulation are those that cause obstruction to the Left side heart to pump blood into the aorta. These include :
- Coarctation of Aorta ( especially pre Ductal ) : Here there is a constriction of the aorta just before the ductus Arteriosus. So , a persistent Ductus would transport blood from pulmonary circulation into the systemic.
If ductus gets closed , there would be minimal blood flow to the Lower limbs and abdomen.
- Critical Aortic stenosis.
- Left side Hypoplastic heart.
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✓ Duct dependent lesions for pulmonary circulation
-These are lesions where pulmonary blood flow would be severely reduced due to some RV- Outflow tract Abnormality and the only source to the lungs would be through the ductus shunting some blood from aorta into the pulmonary vein.
- These include :
- Critical Pulmonary Stenosis
- Hypoplastic Right heart syndrome
- Tetrology of Fallot
- Tricuspid Atresia
- Ebstein Anomaly
Another important disease is Transposition of the great vessels where this sort of corrects the defect.
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So. We've seen in what conditions we'd like to keep the Ductus Arteriosus open / persistent.
Normally this Ductus closes functionally within 24 hours of birth. And anatomically between 10 and 14 days post natally.
If this persists on its own for a long time it causes a Congenital Heart Disease called Patent Ductus Arteriosus.
This defect is characterised by shunting of blood into the pulmonary trunk constantly during systole and diastole causing a Continuous murmur.
To close this ductus , we could try using Indomethacin / Ibuprofen especially in preterm children.
These drugs inhibit Prostaglandin synthesis , thus causing Ductus Smooth muscle to constrict and eventually close.
So that's all about the ductus !
Happy studying !
And Stay Awesome !
~ A.P.Burkholderia