Dr Swati Prashant
MD Paediatrics
Index Medical College, Indore,MP,India
drprahantw@gmail.com.
www.paediatrics4all.com
 The
most common L →R Shunts are :
 1. VSD : 27%
 2. ASD : 13 %
 3. PDA : 11 % .
 It
constitutes 13 % of all CHD .
 There is an abnormal communication
between the 2 Atrias .
 ASD’ s
are of 3 types .
 1 Ostium Secundum defect : 70% .Defect
is at the fossa Ovalis or rarely superior
or Posterior to fossa .
 2. Ostium Primum defect : 30% .
Defect is
 Defect
is an Endocardial Cushion defect
lying Inferior to fossa . It may be
associated with Mitral Valve defect .
 3. Sinus Venosus defect : 10%
,associated with defect at entry of
SVC in Rt. Atrium .
Haemodynamics
 1. Oxygenated blood from Lt Atrium

↓

Right Atrium

It receives extra blood , causing

Right Atrial enlargement

↓

Large volume of Blood passes through
Normal Tricuspid Valve

Causing Delayed Diastolic Murmur ( DDM ).

↓

large Volume is received by RV

Rt. Ventricle enlarges ( cardiac impulse

↓

Large vol . Thru. Pulmonary
Artery

causes Ejection Systolic Murmur
 & delayed closure of P2 , Therefore A2 -P2

WIDE split & loud p2 . As age
advances PH OCCURS .

 Mild
effort intolerance
 Chest infections
 CCF
Rare .
 Parasternal Impulse
 A2—P2 Wide split fixed
 Systolic Thrill & Murmur in P2 area
due to flow thru. Pulmonary valve .
.
 Complications
are rare
 After age 20 yrs. PH occurs .
 ECG---RVH & RBB
 X-Ray---mild cardiomegaly , RAH ,RVH
,PA prominent , plethora.
 TREATMENT
:
 1. T/t of Infections , ccf
 2. Surgery
 Common syndromes asso. With ASD :
 Down’s Syndrome , Holt Oram syndrome ,
Lutembachker , Noonans syndrome .
 It
is most common amongst the CHD .
 Constitutes 27% of all CHD’s .
 Location : 90% of VSD are in
Membranous part of the Septum
 Others occur in Muscular
part & can
be multiple .
 Syndromes:
Trisomy 13 - 15 , 17-18.
Absent Radius & Ulna , poly &
Syndactyly .
HAEMODYNAMICS
 Left → Right shunt .
 Lt. Ventricle blood →enters Rt.
Ventricle through the defect .
 At the same time Rt. Ventricle is also
contracting. So the blood is almost
directly
going to Pulmonary Artery .
 Large vol. Thru. PA → CAUSE Ejection
Sys. Murmur + delayed P2 , due to
delayed empting .Also there is early
empting of LV causing early A2 .

 Therefore
there is a wide split A2 P2
.
 ↑ blood in LA causes LA
ENLARGEMENT.
 ↑ blood flow thru. Mitral valve causes
DDM at apex .
 Shunt itself causes
PANSYSTOLIC
Murmur as blood is going thru. The
shunt in systole ----in Tricuspid area -lt. Sternal border 3,4,5 space .
 Symptomatic
around 6 –10 wks.
 CCF develops .
 Palpitation , dyspnea on exertion .
 Frequent chest infections .
 Wide pulse pressure .
 Hyperkinetic precordium with systolic
Thrill .
 Cardiomegaly with Left ventricular
Apex .
 Wide
split 2 nd HEART SOUND
 P2 accentuated
 Pansystolic Murmur at Lt. Sternal
border ( 3 ,4 ,5th IC SPACE .
 ECG :
1) RVH initially & in newborn
.
 2) IN small & mod . Size VSD ,RVH
comes to normal after ↓ of pulmonary
resistance .
 3)
In large VSD without PAH there
is LVH
 4) In large VSD + PS /PAH : ECG
shows RVH + LVH or purely RVH .

X-RAY CHEST
 1. LVH—Depends on size of shunt .
 2. Plethora
 3. Aorta N or small in size .
 4.
LAH in large shunts .
 5. If VSD is small : Heart size normal,
pulmonary vasculature is normal .
 6. If VSD + PS : Heart size is normal ,
normal lung fields .
 7. If VSD + PAH : Heart size is normal
,but lung fields are Plethoric .
 Small
VSD : PSM + normal P2 ,
disappearance of murmur + ECG becomes
Normal .
 Large VSD : RV pressure = LV pressure ,
therefore murmur becomes softer + PAH
+ accentuated P2
 Large VSD + PS : ejection systolic
murmur +↑ RV pressure + normal PA
pressure + P2 soft
Medical : T/t --CCF , Infections ,
Anemia , Endocarditis .
Surgery : Indications
1. CCF in infancy not responding to
medical t/t .
2. L→ R shunt is large
3. VSD ( large) + PS / PH or AR .
4. Surgery : contraindicated in PAH +
reversal of shunt .
 Surgery
: Closure of VSD
WITH A
Dacron patch , through Rt. Atrial
approach .
 Surgery is advised if PAH develops ,
within 2 yrs.
 Complications of Surgery :
 Complete Heart Block , residual VSD .
 It
is a communication between the
Pulmonary Artery & the Aorta .
 Aortic attachment is just distal to the
Left Subclavian Artery .
 Ductus arteriosus is normally present in
fetal life .
 It closes normally after birth .
 It constitutes 11% of all cardiac defects
.
 L→R
shunt from Aorta
to Pulmonary
Artery .
 Flow is both during systole as well as
Diastole , as pressure is always higher
in Aorta
with normal Pulm . Artery .
 This L →R shunt causes murmur .
Murmur starts in systole after 1st HS
& Continues in Diastole but with
diminished intensity , therefore
Continuous murmur.
 LA
receives large amt. of blood
,therefore LA enlarges In size .
 ↑ blood flow through
Mitral valve ->
causes accentuated 1st HS + DDM .
 LV also receives more blood →
overloading → prolongation of lt.
Ventricular systole & ↑ in LV size .
 Prolonged systole →
cause delayed
closure of Aortic valve ---late A2 .
 Late
A2 causes paradoxical split in
large shunts .
 Large vol. Coming to Aorta causes
Aortic dilatation ( ascending ) , this
causes Ejection click & Ejection
systolic murmur , but this is masked
by continuous murmur .
 Patient
becomes symptomatic early in
life .
 Develops CCF around
6-10 wks of life
, or even earlier within 7 days of
birth with murmur + ccf .
 In older children
there is effort
intolerance , palpitation , chest
infections .

 As
there IS a leak of blood to PDA
from systemic blood there is a wide
pulse pressure + collapsing pulse .
 Prominent CAROTID pulsations
+
features L → R shunt is s/o PDA .
 Cardiac impulse & Apex Beat are
Hyperkinetic s/o LVH due to ↑ blood
Volume .
 Continuous
/ systolic murmur + Thrill
at Lt. 2nd space .
 SO IF SHUNT IS LARGE :
 1. 1 st HS is accentuated due to ↑
Mitral flow .
 2. 2 nd HS
is narrow /paradoxically
split
 3. P2 is louder than
normal .
 Continuous murmur best heard in P2
AREA
 ECG
: LVH--- ‘ Q’ & tall ‘T’ waves are
characteristic of Lt . Ventricular vol.
Overload .
 X-Ray chest : cardiomegaly with LV
enlargement .( large shunt -- large
size, large shunt --narrow split , small
shunt --- no split .)
 LA enlarged , Ascending Aorta (
knuckle) prominent .
 In
Newborn & infants ---PH is +nt at
birth causing Ejection syst. Murmur .
 Later as PH ↓ the murmur becomes
continuous .
 CCF same as in VSD .
 In PDA ,PH later due to flow develops
earlier than VSD .
 As PH develops later diastolic
component ↓ ,so the murmur becomes
Ejection syst. Murmur .
 If
PH --P2 is loud + DDM +nt
 If PS --P2 is soft or N + no DDM
 If L→ R becomes R→L there is no
murmur , but DIFFERENTIAL CYANOSIS
is present
 In PDA + PH
causing reversal .
 For
closure of PDA
 1. Indomethacin ( prostaglandin
synthetase inhibitor ) given orally
 Dose is 0.1 mg /kg / day 12 hourly
in 3 doses.
 Hepatic / Renal / Bleeding tendency----CI
 2. Surgical ligation
PDA .
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