P atent ductus arteriosus Patent ductus arteriosus is a communication between the pulmonary artery (Mostly Left Pulmonary Artery ) and the aorta

The Persistence of function and patency of ductus arteriosus beyond 24 hours after birth is considered as PDA (Normally closes soon after birth)

The Aortic attachment of Ductus Arteriosus is just distal to the Subclavian Artery.

In Fetal Life, Patency is maintained by Prostaglandins and High O2 Levels.

Causes:1.Prematurity2.Maternal Rubella

Demography:Female :Male = 2:1

Hemodynamics: In PDA, blood flows from Aorta to Pulmonary artery because aortic

pressure is higher than the Pulmonary artery pressure.This is Left Right Shunt.

The flow through the ductus occurs both during systole and diastole as then pressure gradient is maintained throughout the cardiac cycle between the 2 great Arteries. This manifests a continuous murmur that is : Murmur starts in Systole after S1 and Reaches the Peak at S2.

Larger blood volume Passes through Pulmonary circulation (Blood from Right side of heart plus some blood from Aorta) this causes Pulmonary Hypertension (Xray shows Pulmary Plethora) and Left ventricular hypertrophy.

Paradoxical Splitting of S2:A2 occurs after P2Reason : Extra Volume passes through aortic area causes delayed closure of aortic valve.

SYMPTOMS: Dyspnoea on Exertion Frequent Chest Infections Retarded physical growth

SIGNS: Tachypnoea Tachycardia Bounding pulse (wide Pulse Pressure) Continuous MACHINERY MURMUR (Auscultate @ 2nd ICS) Accentuauted S1 (Due to Increased blood volume from Left

Atrium to Left Ventricle through Mitral valve) Paradoxical split of S2 Prominent Apical impulse Continous thrill

Complication : CHF Infective Endocarditis Pulmonary Hypertension Pneumonia Aneurysm of PDA Eisenmenger’s syndrome (reversal of shunt)

Investigations:1.Chest Xray :

Pulmonary PlethoraPulmonary oedemaEnlarged Cardiac Shadow

2.ECG :

Left Ventricular Hypertrophy

3.2D Echo :

Ductal Flow ( Prominent in Diastole)

Treatment:

Medical – NSAIDS : INDOMETHACINSurgical – Surgical Ligation.