Patent ductus arteriosus

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.