Ventricular Septal Defects (VSD)
• Most Common CHD.
• Three important things with VSD:
• pulmonary vascular resistance.
• The amount of flow crossing a VSD depends
on the size of defect and the pulmonary
Location of VSD
• Location of the VSD – prognostic and repair
• The VSDs are subdivided according to the part of
the septum they occur in :
• perimembranous (adjacent to the tricuspid
pulmonary vascular resistance.
• At birth, the pulmonary vascular resistance is
normally elevated, thus, even large VSDs are not
symptomatic at birth.
• Over the first 6-8 weeks of life, pulmonary
vascular resistance normally decreases.
• More blood flows through the lung and into the
• However, in VSD, the amount of shunt increases,
and symptoms may start to develop.
• The size of the VSD affects the clinical
Size of VSD
Small (< 3 mm in
Moderate (3-5 mm in
Large (6-10 mm in
-Between 80% and 85% of
-All close spontanously
-Muscular close sooner
-Least common group of
-Without evidence of CHF or
pulmonary hypertension, may
be followed until spontaneous
- develop CHF and FTT by age
-Usually requires surgery.
• VSD permits a left-to-right shunt to occur at the
ventricular level with 3 adverse hemodynamic
1. left ventricular (LV) volume overload,
2. increased pulmonary blood flow,
3. compromise of systemic cardiac output.
Small VSD: Asyptomatics
Heart failure with breathlessness
failure to thrive.
Recurrent chest infections
• Clinical findings (murmur)
– Grade II-IV/VI,
– medium- to high-pitched,
– pansystolic murmur
– heard best at the lower left sternal border with
– radiation over the entire precordium
Demonstrates the anatomy defect, haemodynamic effects and severity of
• Small VSD:
– Chest X-ray & ECG - normal
• Large VSD:
• Enlarged pulmonary arteries
• ↑ Pulmonary vascular markings
• Pulmonary oedema
ECG : Biventricular hypertrophy and signs of pulmonary HPT right
ventricular enlargement and hypertrophy(if not treated)
X-Ray chest PA View
There is cardiomegaly, prominent main pulmonary artery segment and right
pulmonary artery. Enlarged left pulmonary artery shadow is seen below the left
cardiac border, within the cardiac silhouette. The enhanced vascular markings are
visible on the right side whereas it is obscured by the cardiac shadow on the left
– Most will close spontaneously. Ensure by the
disappearance of the murmur, normal ECG on
follow up, normal echocardiogram.
– While the VSD is present, for prevention of
bacterial endocarditis :
• Maintain good dental hygiene
• Antibiotic prophylaxis before dental extraction
or any operation where there’ll be bleeding
– Surgical closure may not be required
• Initial treatment (Medical) – diuretics and ACI
(captopril) or digoxin.
• Continued poor growth or pulmonary HPT
requires closure of the defect.
• Most VSDs are treated by surgery. But muscular
defects by devices placed at cardiac
• Surgery is usually done at 3-6 months of age for :
• Managing heart failure and failure to thrive.
• Prevent permanent lung damage from pulmonary HPT
and high blood flow.
Atrial Septal Defects (ASD)
• Due to failure of septal growth or excessive reabsorption of tissue.
• are the most common congenital cardiac lesion presenting in
– Secundum ASD (80%)
– Primum ASD or partial atrioventricular septal defect
• Ostium primum ASDs may occur in isolation but most
commonly present with a cleft in the anterior leaflet of the
mitral valve(partial atrioventricular septal defect )
– Sinus venosus defect (least common)
• occurs in the upper atrial septum
• Associated with anomalous pulmonary venous return
• Shunting across an atrial septal defect is left to right
• The degree of this shunting is dependent on;
- the size of the defect
- the relative vascular resistance in the pulmonary and systemic
• Resistance in the pulmonary vascular bed is commonly normal in
children with ASD, and increase in volume load is usually well tolerated
• The chronic significant left-to-right shunt can alter the pulmonary
vascular resistance leading to pulmonary arterial hypertension, even
reversal of shunt and Eisenmenger syndrome (if not treated)
-breathlessness, tiredness on
- Recurrent chest infections/wheeze
- Heart failure
-Arrhytmias (4th decade onwards)
-A fixed and widely split 2nd heart
-An ejection systolic murmur (soft),
upper left sternal edge
-Partial AVSD – apical pansystolic
murmur from AV valve regurge.
- Usually normal
- enlarged pulmonary arteries
-increased pulmonary vascular
- Documents type, size and
direction of shunt
- The mainstay of diagnostic
-provide strong diagnostic clue:
-Both: right bundle branch block
-secundum ASD – right axis deviation
-partial AVSD – left axis deviation (superior axis)
• If significant shunt is present at around 3
y/o, closure is recommended.
• Cardiac catheterization with insertion of an
occlusion device (closure device).
• Prophylaxis for subacute bacterial
• Surgical correction at 3-5 y/o to prevent
right heart failure and arrhythmias in later
Prognosis & Complications
• ASDs detected in term infants may close
spontaneously. Secundum ASDs are well tolerated
during childhood, and symptoms do not usually appear
until the 3rd decade or later.
− Congestive heart failure
− Pulmonary hypertension
− Infective endocarditis
− Surgery may be associated with a long-term risk of
atrial fibrillation or flutter. The risk of infective
endocarditis exists during the first 6 months after
Endocardial cushion defects
• also referred to as atrio-ventricular canal defects,
• may be complete or partial .
• The defect occurs as the result of abnormal
development of the endocardial cushion tissue,
resulting in failure of the septum to fuse with the
endo-cardial cushion; this results in abnormal
atrioventricular valves as well.
• The complete defect results in a primum ASD, Inlet
VSD, and cleft in leaflet of mitral and cleft leaflet of the
• In addition to left-to-right shunting at both levels, there
may be atrioventricular valvular insufficiency.
• The symptoms of CHF usually develop as the pulmonary
vascular resistance decreases over the first 6 to 8 weeks of
• Pulmonary hypertension resulting from increased
pulmonary circulation often develops early; this results in a
• The presence of murmurs varies depending on the balance
If intracardiac dynamics are balanced, there is little
shunting and no significant murmur.
If dynamics are less balanced, murmurs consistent with an
ASD, VSD, or valvular insufficiency may be heard.
Growth is usually poor.
Many children with Down syndrome have complete
endocardial cushion defects.
• Imaging Tests:
o The diagnosis usually is made with echocardiography.
o A chest radiograph reveals cardiomegaly with
enlargement of all chambers and the presence of
• The ECG reveals left axis deviation and combined
ventricular hypertrophy and may show combined
Initial treatment (Medical) – diuretics and ACI
(captopril) or digoxin diuretics for treatment of CHF.
Surgical repair of the entire defect ultimately is
Patent Ductus Arteriosus (PDA)
• The ductus arteriosus allows blood to flow from the
pulmonary artery to the aorta during fetal life. This
changes to the opposite after birth.
• In term infants, it normally closes shortly after birth.
Failure of the normal closure of it by a month post
term is due to a defect in the constrictor mechanism
of the duct.
• In preterm infants, the PDA is not from CHD but due to
• Higher aortic pressure, blood shunts left to right through
• The magnitude of the excess pulmonary blood flow
− The internal diameter PDA.
− The length PDA
− Relationship of the pulmonary vascular resistance to the
systemic vascular resistance.
• If the PDA is large, pulmonary artery pressure may be
elevated to systemic levels during both systole and diastole.
Extremely high risk for the development of pulmonary
vascular disease if left unoperated.
-Depend on size of PDA
- Small – asymptomatic
- Moderate to larger shunts –
symptoms of CHF or even pulmonary
- Continuous machinery murmur
beneath the left clavicle
- Widened pulse pressure collapsing
or bounding pulse
Chest X-ray & ECG
- Usually normal unless the PDA is large
- Features seen are indistinguishable from
- Duct should be readily identified by
- Small PDA – closure is recommended
due to the risk of bacterial endocarditis
- Moderate and large PDA – initially
diuretics & digoxin, but eventually
- Closure is with a coil or occlusion
device introduced via cardiac catheter
at abuot 1 y/o
Coarctation of the aorta
• It is almost always juxtaductal in position.( the
part near where the ductus arteriosus
• During development of the aortic arch, the
area near the insertion of the ductus
arteriosus fails to develop correctly, resulting
in a narrowing of the aortic lumen.
• Timing of presentation depends primarily on
the severity of obstruction and associated
• Symptoms and Signs:
SEVERE : Shock
MODERATE : CHF,
MILD : leg discomfort with exercise,
headache, or epistaxis.
• Classically the femoral pulses are weaker and
delayed compared with the radial pulses.
• The blood pressure in the lower extremities is
lower than that in the upper extremities
• hypertension (upper extremity),
• The murmur of coarctation is typically best heard
in the left interscapular area of the back.
• If significant collaterals have developed,
continuous murmurs may be heard throughout
• An abnormal aortic valve is present
approximately 50% of the time, causing a systolic
ejection click and systolic ejection murmur of
- Ventricular Septal Defect
- Persistent Ductus
- Atrial Septal Defect (ASD
- Aortic Stenosis
Teralogy of Fallot
transposition of the
Imaging Studies: Echocardiography shows the
site of coarctation and associated lesions.
• In older children, the ECG and chest x-ray
usually show left ventricular hypertrophy and
a mildly enlarged heart.
• CXR: Rib notching may also be seen in older
children (>8 years old) with large collaterals.
Balloon angioplasty or surgical repair of the
coarctation are most commonly performed.
• Cyanosis:A bluish discoloration of skin and
mucous membrane due to excessive
concentration of reduced hemoglobin
(deoxygenated) in the blood.
Central vs peripheral
• Central cyanosis:
– Seen on tongue as blue colour
– Associated with a fall in arterial blood O2 tension.
• reduced(deoxygenated) Hb >5g/dL
• SpO2= <85% by pulse oximetry test.
• Peripheral cyanosis:
– Blueness of hand and feet
– Due to cold or circulatory disorder (e.g: DVT)
– Can also occur in severe central cyanosis
Tetralogy of Fallot (TOF)
• Tetralogy of Fallot is the most common cyanotic
congenital heart defect.
• Anatomically, there are four structural defects:
VSD, pulmonary stenosis, overriding aorta and
right ventricular hypertrophy.
• Tetralogy of Fallot is believed to be due to
abnormalities in the septation of the truncus
arteriosus into the aorta and pulmonary arteries
that occur early in gestation (3 to 4 weeks).
• The degree of cyanosis depends on the
amount of pulmonary stenosis.
• Infants initially may be acyanotic.
• Older children+ long standing cyanosis+ not
– Dusky blue skin
– Grey sclerae with engorged blood vessel
– Marked clubbing of fingers and toes
• A pulmonary stenosis murmur is the usual initial
• If the pulmonary stenosis is more severe, or as it
becomes more severe over time, the amount of right-
to-left shunting at the VSD increases, and the patient
becomes more cyanotic.
• With increasing severity of pulmonary stenosis, the
murmur becomes shorter and softer.
• single S2 and right ventricular impulse(heave) at the
left sternal border are typical findings.
• hypoxic ("Tet") spells
• Independent of hypoxic spells, patients with tetralogy
are at increased risk for cerebral thromboembolism
and cerebral abscesses resulting in part from their
right-to-left intracardiac shunt.
• Hypoxic spells/ paroxysmal hypercyanotic
attacks (1st 2years of life)
– Severe hypoxia tissue acidosis breathlessness
– Rapid increase in cyanosis
– Restless and agitated
– Inconsolable crying
– An ambulatory toddler may squat
– Severe spells:
• Prolonged unconsciousness and convulsions
• OR death
• The ECG usually has right axis deviation and right
• The classic chest x-ray finding is a boot-shaped
– Small heart
– Uptilted apex (boot shaped)
– pulmonary artery ‘bay’= concavity of L heart border
– Oligaemic lung fields
• Echocardiography: The diagnosis usually is made
• The natural history of tetralogy of Fallot is progression of
pulmonary stenosis and cyanosis.
Treatment of hypoxic spells consists of
• oxygen administration,
• placing the child in the knee-chest position (to increase venous
• and giving morphine sulfate (to relax the pulmonary infundibulum
and for sedation).
• If necessary, the systemic vascular resistance can be increased
acutely through the administration of an α-adrenergic agonist
• β-adrenergic antagonists (propranolol) decrease muscular spasm.
Complete surgical repair with closure of the VSD and removal or
patching of the pulmonary stenosis can be performed in infancy.
Subacute bacterial endocarditis prophylaxis is indicated.
• Cyanosis is always present
• Finger clubbing
• Quiet tachypnea
• Single S2
• Usually no murmur
• Signs of CHF in children with transposition and
a large VSD.
Transposition of the Great Arteries
• It is the most common cyanotic lesion to present in the
newborn period .
• TGA is ventriculoarterial discordance secondary to
abnormalities of septation of the truncus arteriosus.
• In TGA, the aorta arises from the right ventricle, anterior
and to the right of the pulmonary artery, which arises from
the left ventricle.
• This transposition results in desaturated blood returning to
the right heart and being pumped back out to the body,
while well-oxygenated blood returning from the lungs
enters the left heart and is pumped back to the lungs.
• Without mixing of the two circulations, death occurs
• Mixing can occur at the atrial (ASD), ventricular (VSD), or
great vessel (PDA) level.
• ECG findings typically include right axis
deviation and right ventricular hypertrophy.
• The chest x-ray reveals increased pulmonary
vascularity, and the cardiac shadow is
classically an egg on a string created by the
narrow superior mediastinum.
• Echocardiography shows the transposition of
the great arteries, the sites and amount of
mixing, and any associated lesions.
• Simple (TGA) with intact ventricular septum:
– IV Prostaglandin E1 infusion
– Early Balloon arterial septostomy (BAS)
– Surgery: arterial switch procedure (2-4weeks of age)
• TGA with VSD:
– No treatment during neonatal period, but may
develop heart failure 1-2months age
– Elective one-stage arterial switch operation + VSD
closure before three months of age.