Patent ductus arteriosus is an abnormal opening between the pulmonary artery and the aorta that fails to close after birth. It causes excess blood to flow from the aorta to the pulmonary artery, resulting in a left-to-right shunt. Common symptoms include dyspnea, frequent chest infections, and retarded growth. Signs include a bounding pulse, continuous machinery murmur, paradoxical split of S2, and pulmonary hypertension seen on chest X-ray. Treatment options include medical management with indomethacin or surgical ligation to close the opening.

1. Patent ductus arteriosus
Patent ductus arteriosus is a communication between the pulmonary artery
(Mostly Left Pulmonary Artery ) and the aorta
 The Persistence of functionandpatency of ductus arteriosus beyond24
hours after birthis consideredas PDA (Normally closes soonafter birth)
 The Aortic attachment of Ductus Arteriosus is just distal tothe Subclavian
Artery.
 In Fetal Life, Patency is maintainedby Prostaglandins andHighO2 Levels.
Causes:
1.Prematurity
2.Maternal Rubella
Demography:
Female :Male = 2:1
Hemodynamics:
 In PDA, blood flows from Aortato Pulmonary artery because aortic
pressure is higher thanthe Pulmonary artery pressure.
This is Left  Right Shunt.
 The flow throughthe ductus occurs both during systole anddiastole
as thenpressure gradient is maintainedthroughout the cardiac
cycle betweenthe 2 great Arteries. This manifests acontinuous
murmur that is : Murmur starts inSystole after S1 and Reaches the
Peak at S2.
 Larger blood volume Passes throughPulmonary circulation(Blood
from Right side of heart plus some blood from Aorta) this causes
Pulmonary Hypertension(Xray shows Pulmary Plethora) and Left
ventricular hypertrophy.

2.  Paradoxical Splitting of S2:
A2 occurs after P2
Reason: ExtraVolume passes throughaortic areacauses delayed
closure of aortic valve.
SYMPTOMS:
 Dyspnoeaon Exertion
 Frequent Chest Infections
 Retardedphysical growth
SIGNS:
 Tachypnoea
 Tachycardia
 Bounding pulse (wide Pulse Pressure)
 Continuous MACHINERY MURMUR (Auscultate @ 2nd
ICS)
 AccentuautedS1 (Due toIncreasedbloodvolume from Left
AtriumtoLeft Ventricle throughMitral valve)
 Paradoxical split of S2
 Prominent Apical impulse
 Continous thrill
Complication:
 CHF
 Infective Endocarditis
 Pulmonary Hypertension
 Pneumonia
 Aneurysmof PDA
 Eisenmenger’s syndrome(reversal of shunt)

3. Investigations:
1.Chest Xray :
Pulmonary Plethora
Pulmonary oedema
EnlargedCardiac Shadow
2.ECG :
Left Ventricular Hypertrophy
3.2D Echo :
Ductal Flow( Prominent in Diastole)
Treatment:
Medical – NSAIDS :INDOMETHACIN
Surgical – Surgical Ligation.