CONGENITAL
HEART DISEASE
(CHD)

CONGENITAL HEART DISEASE (CHD)
They are typically arise in the 3rd–8th week of
gestation.
The incidence of significant cardiac abnormalities is
8:1000 live births.
In neonates and children with CHD, 15% will have
more than one cardiac abnormality and 15% will
have another extra-cardiac abnormality.
There are approximately nine 'common'
congenital heart defects that make up about 90%
of all cases of congenital heart disease; the
remaining 10% are rare complex cardiac defects.

CONGENITAL HEART DISEASE (CHD)
Aetiology :
There is often no obvious aetiology; most would
appear to be multifactorial with both genetic and
environmental influences:
Maternal (environmental) factors
 Infection
 Rubella Disease
 DM, Maternal DM ,Drugs/medications Alcohol
abuse,
Genetic factors
 Marfan syndrome
 Trisomy 21 , trisomy 18 (Edwards syndrome)
 Turner syndrome,

CONGENITAL HEART DISEASE (CHD)
Classifications:
Congenital heart disease can be broadly
classified according to the presence or
absence of cyanosis,
The presence of central cyanosis,
blueness of the trunk and mucous
membranes, is due to > 3-5 g/dl of
deoxygenated haemoglobin in the
arterial circulation.

CONGENITAL HEART DISEASE (CHD)
Classifications:
I. Cyanotic congenital heart diseases
make up 1/3 of cases, and are usually
more complex:
1. A right to-left shunt resulting in decreased
pulmonary blood flow.
Many of these lesions consist of a septal
defect in con-junction with a right-sided
obstructive lesion, producing an obligatory
right-to-left shunt.
The most common type
Tetralogy of Fallot (TOF).

CONGENITAL HEART DISEASE (CHD)
Classifications:
2. Parallel systemic and
pulmonary blood flow rather
than in series.
This is incompatible with life if there is no
mixing, so typically neonates have a
patent foramen ovale that allows some
mixing of the two circulations at this
level.
The most common example of this is
Transposition of the Great Arteries
(TGA).

CONGENITAL HEART DISEASE (CHD)
Classifications:
3. Defects in the connections to the
heart
where there is mixing of the systemic and
pulmonary flows.
An example of such a complex lesion is
Total Anomalous Pulmonary Venous
Drainage

CONGENITAL HEART DISEASE (CHD)
Classifications:
II. Acyanotic congenital heart
diseases represent : 2/3 of the cases
1. Left-to-right shunt with increased
pulmonary blood flow:
which causes an increase in volume work
on the heart e.g. patent ductus
arteriosus (PDA), atrial septal defect
(ASD) and ventricular septal defect
(VSD).

CONGENITAL HEART DISEASE (CHD)
Classifications:
2. An obstruction of the blood flow
across a heart valve on the left
heart:
such as aortic stenosis or in the aorta
itself as occurs with coarctation of the
aorta, leading to an increase and work
of the heart.

I. Cyanotic CHD

Fallot's tetralogy
This is the most common cyanotic
congenital heart disease and accounts for
about 4-6% of all congenital heart
diseases.
The four intracardiac lesions originally are:
1. Pulmonary (typically infundibular or
subpulmonary) stenosis;
2. Right ventricular hypertrophy
3. VSD;
4. Overriding aorta

Fallot's tetralogy
Four abnormalities

Clinical features:
The degree of cyanosis depends on the degree of pulmonary
stenosis.
If there is significant pulmonary stenosis to virtual pulmonary
atresia, presentation is in the neonatal period because of duct
dependency.
As pulmonary stenosis progresses, cyanosis typically develop with
in the first year of life.
Classically, hypercyanotic spells are thought to be due to
infundibular or subpulmonary muscle spasm.
Squatting is an adaptation by the child to such hypoxic spells. This
increases systemic vascular resistance and the venous return to
the head.
Physical examination: moderate systolic ejection murmur which
may disappear during a spell.
Continuous murmurs may be found in patients with
aortopulmonary collaterals .
Clubbing develops in older children, usually after 6 months of age.

Investigations:
 ECG : right atrial and right ventricular
hypertrophy.
 Chest x-ray: 'boot-shaped' heart with
poorly developed lung vasculature.
 The Echocar-diography is diagnostic .
 Cardiac catheterization prior to
surgery.

Indications for surgery
These are based on clinical
progression include:
 Severe cyanosis ( oxygen
saturation < 80% on room air),
 Hypercyanotic spells,
 Dyspnoea on effort,
 Syncopal attacks and
 Polycythaemia.

Surgical options (Curative)
 When the infant becomes symptomatic, a complete
primary repair may be performed as a first
procedure, or
 if asymptomatic, elect for total primary repair early,
ideally with in the first 6 months, but usually within
the first 3 years.
 This approach has the advantage of reducing the
number of operations, restores normal oxygen
saturation earlier in life and so helps development
and, by repairing the defect early, leads to less right
ventricular hypertro-phy, which may reduce the
frequency of late arrhythmias.

Surgical options (Curative)
•Reapire of VSD
Enlagement of
the pulmonary
trunk

Surgical options (Palliative)
 Such palliative procedures divert systemic blood into the
pulmonary circulation and may be used to improve
oxygenation.
 Many types of systemic-to-pulmonary artery shunts have
been described such as left subclavian to pulmonary
artery shunt (Blalock-Taussig) or other modifications.
 The results of surgery are good with late survival at 5-10
years following correction of tetralogy is 95%, with an
operative mortality for a repair of between 5% and 10%,
and an incidence of reoperation following tetralogy repair
of 5-10%.

Surgical options (Palliative)

Transposition of great arteries
(TGA)
Is the second most common CHD, making up 2.5-5% of all
congenital heart disease, and is the most common cause
of cyanosis from a congenital cardiac defect discovered in
the new-born period.

Clinical features
 Severe central cyanosis presenting in the first 48
hours of life, with the cyanosis progressing in the
first week.
 If there is a large atrial septal defect or ventricular
septal defect there may be minimal cyanosis
initially.
Investigations:
 The chest radiograph: pulmonary plethora, with the
heart having an 'egg on its side' appearance, with a
small pedicle (aorta in front of pulmonary artery).
 Cardiac catheterization and echocardiography
confirm the diagnosis and delineate the anatomy.

Indications for surgery
 The outcome for infants with TGA in the
first year of life without some form of
intervention to increase systemic and
pulmonary venous admixture is death in
80-90% of cases.
 Initial palliation is by percutaneous
(Rashkind) balloon atrial septostomy, or
alternatively intravenous prostaglandin to
keep the ductus open.
 Definitive repair is usually the Total Arterial
Switch procedure, which has replaced the
atrial switch or baffle (Mustard or Senning)
operation because of reduced long-term
complications

Cardiac Surgery
II. Acyanotic CHD

I. Patent ductus arteriosus
Accounts for 8-12% of congenital
heart disease.
The ductus arteriosus, a normal
fetal communication, facilitates
the transfer of oxygenated blood
from the pulmonary artery to the
aorta shunting blood away from
the lungs.
Normally, functional closure of the
ductus occurs within a few hours
of birth; it is abnormal if it
persists beyond the neonatal
period

Patent ductus arteriosus
Clinical features
 Small shunts usually causing no symptoms, and few signs
apart from a continuous machinery murmur in the left
sec-ond intercostal space.
 Larger ducts cause cardiac failure and can uncommonly
lead to shunt reversal with cyanosis and clubbing.
Investigations :
Echocardiography with Doppler colour flow.
Cardiac catheterisation is performed only if additional
lesions are suspected.
Indications for surgery:
 After 6 months of age, spontaneous closure of PDA is
rare. Most should be closed by the preschool age.
 In the adult, surgical treatment is indicated if there is a
persistent left to right shunt, even in the presence
pulmonary hypertension.

Patent ductus arteriosus
Surgical options
 In the premature infant, pharmacological closure
of the patent ductus arteriosus with indomethacin
is generally successful.
 If medical treatment to close the ductus is
unsuccessful, the lesion may be treated by
interventional cardiology, using an umbrella or
coil duct occlusion device inserted
percutaneously.
 Surgical closure via a left thoracotomy, if the
lesion is very large or the patient very small is
preferred.
 This can be accomplished by either ligation or
division of the patent ductus arteriosus.

II. Coarctation of the aorta
 This accounts for 6-7% of
congenital heart disease
and is defined as a
haemodynamically
significant narrowing of
the aorta, usually in the
descending aorta just
distal to the left
subclavian artery, around
the area of the ductus
arteriosus

III. Coarctation of the aorta
Pathophysiology
 The upper body is well perfused but
the lower body, including the
kidneys, is poorly perfused leading
to fluid overload, excess renin
secretion and acidosis.
 Children with coarctation are
usually male and, if it occurs in
females, it is suggestive of Turner
syndrome.
 There are several common
associated lesions, including
bicuspid aortic valve, ventricular
septal defect.

Coarctation of the aorta
Clinical features
 The child may appear well in the first few days
of life because the coarctation is bypassed
by the ductus arteriosus and oxygenated
blood reaches the entire systemic circulation.
 As the ductus closes, the child becomes
progressively more unwell.
 Hypertension is a common presenting
problem in older children, often just upper
body hypertension with development of
enormous collateral vessels that may cause
ribnotching and flow murmurs over the scapula.
 Other symptoms include prominent pulsation
in the neck, tired legs or intermittent
claudication on exercise.

III. Coarctation of the aorta
Indications for surgery
 Neonate with severe failure, operation
indicated at time of diagnosis
 If cardiac failure delay 3-6 months
 Increased incidence of recurrent
stenosis if operated at less than 3
months
 Increased incidence of hypertesion if
coarctation is repaired beyond infancy

III. Coarctation of the aorta
Surgical options
 Operative options include
resection of the coarctation and
end-to-end anastomosis or the
use of the left subclavian artery
as an onlay flap.
 In the older patient, th
subclavian flap opration is not
feasible and resection with end-
to-end anastomosis,
interposition graft or a 'jump'
graft are preferred.
 Percutaneous balloon dilatation
is an alternative procedure in
older children and adults and, in
particular, for recoarctation.

IV. Atrial Septal Defect (ASD)
 ASD is a defect in the
septum between the left
and right atria leading to
a left-to-right shunt.
 It accounts for
approximately 6-7% of
all congenital heart
disease and is more
common in females.
 There are three
commonly recognised
atrial septal defects.

IV. Atrial Septal Defect (ASD)
Symptoms and Signs
 Most small ASDs are asymptomatic.
 Larger shunts may cause exercise intolerance,
dyspnea during exertion, fatigue, and atrial
arrhythmias sometimes with palpitations.
 Passage of microemboli from the venous
circulation across the ASD (paradoxical
embolization), often associated with arrhythmias,
may lead to cerebral or systemic thromboembolic
disorders.
 Auscultation typically reveals midsystolic (or
ejection systolic) murmur and a widely split, fixed
S2 at the upper left sternal border in children.

IV. Atrial Septal Defect (ASD)
Investigations:
Echocardiography will
define the anatomy and
any other abnormalities
including the direction
of the shunt.

Indications for surgery
 For primum & secundum ASD that fail close to spontaneously
close treatment is aimed at closing the defect if a left-to-
right shunt of 1.5:1 or more is present.
 Closure is performed during the first decade, most small
ostium secundum ASDs (< 3 mm) close spontaneously;
about 80% of those between 3 mm and 8 mm close
spontaneously by age 18 months.
 Asymptomatic children with a small shunt require annual
echocardiography.
 Because these children are at risk of paradoxical systemic
embolization, some centers recommend a catheter-delivered
closure device (eg, Amplatzer Septal Occluder, Cardio-Seal
device) even for small ASDs.
 However, these devices are not suitable for primum or sinus
venosus defects because these defects are near important
structures.

Surgical options
 The traditional method of closure
involves open-heart surgery with
cardiopulmonary bypass (CPB) and
closure of the defect either directly
with sutures, as with most secundum
defects or, if the defect is large,
using a pericardial or synthetic patch.
 Operative mortality for isolated atrial
septal defect repairs is < 1%, with
excellent prognosis.

V. Ventricular septal defects
(VSD)
 These account for 20-30% of congenital heart
disease and affect approximately 2 in 1000 live
births.
 A defect in the interventricular septum that
allows a left-to-right shunting of blood.
 This may occur in isolation or as part of a more
complex set of cardiac abnormali-ties (e.g.
tetralogy of Fallot, complete atrioventricular
canal defect)
 Four major anatomical types of ventricular septal
defect are described, based on the anatomical
subsections of the interventricular septum:

Ventricular septal defects
Investigations
 Chest radiography: may show
cardiomegaly and pulmonary
congestion,
 ECG showing evidence of biventricular
hypertrophy.
 Echocardiography confirms the
diagnosis and can estimate the degree
of shunting across the defect.
 Cardiac catheterisation can quantify the
various pressures within the cardiac
chambers and so assess degree of
pulmonary hypertension.

Ventricular septal defects
Clinical features
Small defects may close or cause little
systemic disturbance.In the first 5 years,
up to 30-50% of ventricular septal defects
close spontaneously. Clinically, a loud
pansystolic murmur can be detected at
the left sternal border due to high
pressure flow between thé ventricles.
Large defects typically present with
congestive cardiac failure in the first 2
months of life. There is a preceding
history of dyspnoea on exertion, failure to
thrive, poor feeding and recurrent chest
infections.

Indications for surgery:
 Approximately one-third of defects close in the first year of
life; a further one-third become relatively smaller in relation
to the growing heart.
 In clinically small defects with a good response to medical
management, it may be appropriate in the infant to 'watch
and wait', although there is a risk of endocarditis.
 Generally, surgical closure is indicated for large defects,
failure to respond to medical therapy,
left-to-right shunts > 2:1, signs of increasing pulmonary
vascular résistance and the presence of complications of
ventric-ular septal defect.
These include
(1) aortic regurgitation, which occurs in about 5% of defects;
(2) infundibular stenosis, which tends to be progressive and
leads to shunt reversal; and
(3) infective endocarditis.

Surgical options
 If the infant is severely symptomatic,
the defect should be closed urgently,
otherwise elective repair is advised
between 1 and 3 years of age in the
asymptomatic patient.
 Most now advocate a primary total
correction, usually at the onset of
symptoms or by 1 year in the
asymptomatic patient.
 Operative mortality for isolated
ventricular septal defect closure is 2-
4%, with long-term prognosis.

QUESTIONS