Congenital heart disease, by dr Shaymaa Fayad, El Nasr Hospital Port said
Blood from the placenta is carried to the fetus by
the umbilical vein. Less than 50% of this enters the
fetal ductus venosus and is carried to the inferior vena
cava, while the rest enters the liver proper from the
inferior border of the liver.
The blood then moves to the right atrium of
In the fetus, there is an opening between
the right and left atrium (the foramen ovale), and most
of the blood flows through this hole directly into the left
atrium from the right atrium, thus by
passing pulmonary circulation.
The continuation of this blood flow is into the left
ventricle, and from there it is pumped through
the aorta into the body.
blood from SVC entering the right atrium but does not
pass directly to the left atrium through the foramen
ovale, enters the right ventricle and is pumped into
the pulmonary artery.
Other special connection between the pulmonary
artery and the aorta found, called the ductus arteriosus,
which directs most of this blood away from the lungs
(which are not being used for respiration at this point as
the fetus is suspended in amniotic fluid).
Because the pulmonary arterial circulation is
vasoconstricted, only about 5% of ventricular outflow
enters the lungs.
The placenta is not as efficient an oxygen exchange
organ as the lungs, so that umbilical venous Po2 (the
highest level of oxygen provided to the fetus) is only
about 30-35 mm Hg.
Intracardiac pressure remains identical between the
right and left ventricles of the human fetus.
during fetal life the Rt ventricle is not only pumping
against systemic blood pressure but is also performing
a greater volume of work than the left ventricle.
Thickening of Rt ventricular wall.
Rt axis deviation in fetal and neonatal period.
Foramen ovale : � Closes at birth due to
1. decreased flow from placenta and IVC to hold open foramen
2.increased pulmonary blood flow and pulmonary VR to left
heart causing the pressure in the left atrium to be higher than
in the right atrium.
3.Some times foramen may remain probe patent for several
Other changes in the heart:
The output from the right ventricle now flows entirely
into the pulmonary circulation.
By the end of the first month, the left ventricular wall is
thicker and the right ventricular wall becomes thinner
The DA constricts at birth, but there is often a small shunt
of blood from the aorta to the left pulmonary artery for a
few days in a healthy, full-term infant .
In premature infants and in those with persistent hypoxia
the DA may remain open for much longer.
Oxygen is the most important factor in controlling closure
of the DA in full-term infants.
When the PO2 of blood passing through the DA reaches about
50 mm Hg, the wall of the DA constricts.
Closure of the DA appears to be mediated by bradykinin( a
substance released by the lungs upon initial inflation), and by
Oxygen� effect on decreasing PG E2 and prostacylcin
As a result of reduced pulmonary vascular resistance, the
pulmonary arterial pressure falls below the systemic level and
the blood flow thrugh the ductus arteriosis is diminished.
The largest decline in pulmonary resistance level usually
occurs within the 1st 2-3 days but may be prolonged for 7
days or more.
Over the next several weeks of life, pulmonary vascular
resistance decreases even further.
This decrease in pulmonary vascular resistance significantly
influences the timing of the clinical appearance of many
congenital heart lesions that are dependent on the relative
levels of systemic and pulmonary vascular resistances.
Congenital heart disease is a category of heart disease that
includes abnormalities in cardiovascular structures that occur
May affect approximately 8 in 1000 live births,
2% in preterm.
Congenital heart defects may produce symptoms at birth,
during childhood, or not until adulthood. Other congenital
defects may cause no symptoms.
Usually the cause of congenital heart disease is
Risk factors include:
1.Genetic or chromosomal abnormalities in the child, such
as Down syndrome.
2.Taking certain medications or alcohol or drug abuse
3.Maternal viral infection, such as rubella (German measles) in
the first trimester of pregnancy.
4.The risk of having a child with congenital heart disease may
double if a parent or a sibling has a congenital heart defect.
a cyanotic CHD that subdivided into:
a-with increased pulmonary blood flow.
b-with normal pulmonary blood flow(stenotic lesion).
cyanotic CHD that subdivided into:
a-with increased pulmonary blood flow.
b-with decreased pulmonary blood flow.
3.Coarctation of the aorta
4.Congenital mitral stenosis
Abnormal communication in
ventricular septum dividing RV
The most common cardiac
anomaly about 15-25% of cases
According to size of the defect divided into
small defect <0.5cm2. Lt to Rt shunt occur due to higher Lt
ventricular pressure, Rt ventricular pressure usually normal →
increased pulmonary blood flow, pulmonary congestion and
Non restrictive VSD:
large defect >1cm2. The pressure in both ventricles is equalized
and the direction and magnitude of the shunt dependent on
the ratio between pulmonary and systemic circulation.
According to size of the defect and pulmonary blood flow and
1. asymptomatic and discovered accidently during routine
examination: small defect or early in first few days of life
where pulmonary pressure and resistance still high.
2. congestive lung symptoms: dyspnea, cough, and repeated
3. low cardiac output symptoms (interrupted feeding, syncope).
4. if not corrected can lead to Eisenmenger syndrome.
5.Low cardiac output signs(small pulse volume, pallor, cold
extremities and excessive sweating when heart failure occur,
duskiness may seen during infection or crying but cyanosis is
6. precordial bulging.
7. biventricular hypertrophy.
8. pulmonary artery diltation (pulsations seen and felt with palpable
9. increase ps2(pulmonary area)
10. Lt parasternal area:
Harsh pansystolic murmur.
Mid diastolic murmur (functional MS) due to increase blood
flow across mitral valve.
Early and small VSD :mainly LT ventricular hypertrophy.
Large VSD :biventricular hypertrophy.
3) Echo (2 dimensional and doppler)
Shows position and size of the defect.
Examining the degree of volume overload in Lt atrium
and ventricle to estimate size of the defect.
Pressure gradient across the defect(restrictive or non
hemodynamics of VSD.
1. Repeated chest infection.
3. Infective endocarditis.
4. Acquired infundibular PS
5. Eisenmenger’s syndrome: increase pulmonary blood flow
with pulmonary congestion →p arteriolar V.C → increase
pulmonary artery pressure → increase Rt sided pressure up
to reversal of the shunt → cyanosis
First reversible V.C then permanent sclerotic changes occur
and permanent V.C and reversal of the shunt.
A significant number (30-50%) of small defects close
spontaneously, most frequently during the 1st 2 yr of
Small muscular VSDs are more likely to close (up to
80%) than membranous VSDs (up to 35%).
Surgical correction for infants with large defects have
repeated episodes of respiratory infection and heart
failure despite optimal medical management.
Abnormal communication in atrial septum.
can occur in any portion of the atrial septum
(secundum, primum, or sinus venosus).
Isolated secundum ASDs account for ≈7% of congenital
The majority of cases of ASD are sporadic; autosomal
dominant inheritance does occur as part of the Holt-
Oram syndrome (hypoplastic or absent radii, 1st-degree
heart block, ASD)
Dependent on the size of the shunt and PVR
In large defects, a considerable shunt of oxygenated blood
flows from the left to the right atrium
Shunting of blood from Lt atrium to Rt atrium during
systole→ Rt ventricular hypertrophy and dilatation
Despite the large pulmonary blood flow, pulmonary
arterial pressure is usually normal because of the
absence of a high-pressure communication between the
pulmonary and systemic circulations.
Pulmonary vascular resistance remains low throughout
childhood, although it may begin to increase in
adulthood and may eventually result in reversal of the
shunt and clinical cyanosis.
May be a symptomatic
Congestive lung symptoms
Complications as HF (rare in early childhood), infective
endocarditis and Eisenmenger’s
Mild Lt pericordial pulg (Rt ventricular enlargement)
Wide fixed split of S2
No murmur because of the shunt
Functional PS → ejection systolic murmur over
Functional tricuspid stenosis →mid diastolic over
Rt axis deviation may be present
Rt ventricular hypertrophy
1.Features of Rt ventricular volume over load e.g.,
flattening and abnormal motion of ventricular septum
2.The location and size of ASD
1.Confirm the presence of the defect
2. Directly measures pulmonary artery pressure and
compare pulmonary artery to systemic artery pressure
Most ASDs <8 mm spontaneously close
Surgical repair of large defect usually after first year of
age and before entering school
Mortality rate in childhood <1 %, more in adulthood
Lt to Rt shunt at both atrial and ventricular level →↑↑
pulmonary blood flow and early onset pulmonary
hypertension (↑↑ risk of eisenmenger’s syndrome)
MI and TI→ volume overload on both Lt and Rt venrticle
The liver is enlarged and the infant shows signs of failure
Early onset of HF (pulmonary congestion, low CO, systemic
Transient episodes of cyanosis
Complete endocardial cushion is common in children with
Auscultatory signs produced by the left-to-right shunt
a normal or accentuated 1st heart sound.
wide, fixed splitting of the 2nd sound.
a pulmonary systolic ejection murmur sometimes
preceded by a click.
If there’s large VSD component, S2 will be single.
additional apical holosystolic murmur caused by mitral
Cardiomegaly with enlargement of all chambers
2. “gooseneck” deformity of the left ventricular outflow tract.
3.The presence of associated lesions such as patent ductus
arteriosus (PDA) or coarctation of the aorta.
4.Doppler echocardiography will demonstrate left-to-right
shunting at the atrial and ventricular level.
is rarely required unless pulmonary vascular disease is
suspected, such as in a patient in whom diagnosis has
been delayed beyond early infancy, especially with
Because of the risk of pulmonary vascular disease
developing as early as 6-12 mo of age, surgical
intervention must be performed during infancy.
Treatment of heart failure if present
Persistence of fetal connection between pulmonary artery and
F:M is 2:1
Increased incidence in prematurity, trisomy 21 and maternal
Lt to Rt shunting → pulmonary congestion and increased
pulmonary artery pressure.
Increase blood passing to Lt ventricle → Lt ventricular
Increase pulse pressure due to run off of blood into
pulmonary artery during diastole
A small PDA is usually asymptomatic
A large PDA will result in heart failure similar to that in
infants with a large VSD.
Retardation of physical growth
Bounding peripheral arterial pulses
a wide pulse pressure
apical impulse is prominent and heaving.
A thrill, maximal in the 2nd left interspace
Increase PS2 over pulmonary area
murmur is described as being like machinery in quality,
starts just after S1 and ends in the late diastole
prominent pulmonary artery with increased pulmonary
the left atrium and left ventricle enlarged
left atrial and left ventricular dimensions are increased.
The ductus can easily be visualized directly and its size
Color Doppler examinations demonstrate systolic or
diastolic (or both) retrograde turbulent flow in the
pulmonary artery, and aortic retrograde flow in diastole
In patients with atypical findings
Demonstrate increased pressure in the right ventricle
and pulmonary artery
presence of oxygenated blood shunting into the
pulmonary artery confirm diagnosis
Indomethacin: for uncomplicated PDA in preterm
Surgical ligation : secondary option for uncomplicated
PDA in preterm, term, infants, and children; first option
for complicated PDA
Catheter device closure: uncomplicated PDA in child
Narrowing in the aorta causing obstruction to
flow usually below origin of Lt subclavian artery at the origin of
Infantil type→ coarctation with arch hypoplasia (sever form)
Adult type → isolated juxtaductal (mild form)
M to F ratio is 2:1
It may be a feature of Turner syndrome
aortic obstruction leading to:
1.High pressure in proximal part of the
aorta → Lf ventricular hypertrophy and
↑↑ blood pressure in the upper part of
2.Low pressure in distal part of the aorta →
low blood pressure in the lower part of
3. Collateral circulation development
4. Sever coarctation+ PDA → differential cyanosis
Usually asymptomatic during infancy and childhood
Heart failure in sever condition
Manifestations of hypertension e.g., headache,
epistaxis, cerebral hemorrhage.
Weak or absent femoral pulsation
Prominent radial pulsation
Radial femoral delay →femoral pulse felt after radial pulse
Blood pressure in LL lower than in UL
Lt ventricular hypertrophy
Ejection systolic murmur best heard in the left infrascapular
a systolic ejection click or thrill in the suprasternal notch
suggests a bicuspid aortic valve (present in 70% of cases).
Mid diastolic murmur at the apex of MS if present
murmur of mild aortic stenosis can be heard in the 3rd
right intercostal space
In older patients with well-developed collateral blood
flow, systolic or continuous murmurs may be heard over
the left and right sides of the chest laterally and
Neonates or infants with more severe coarctation:
1.Initially have signs of lower body hypoperfusion
3.Severe heart failure.
4. On physical examination, the heart is large, and a systolic
murmur is heard along the left sternal border with a loud 2nd
These signs may be delayed days or weeks until after
closure of the ductus arteriosus.
If detected before ductal closure, patients may exhibit
differential cyanosis, best demonstrated by
simultaneous oximetry of the upper and lower
Lt ventricular hypertrophy
Enlarged left subclavian artery→ a prominent shadow in the
left superior mediastinum.
Evidence of left ventricular hypertrophy in older
Neonates and young infants display right or
The segment of coarctation can be visualized
Associated anomalies of the mitral and aortic valve can
also be demonstrated
valuable noninvasive tools for evaluation of coarctation
when the echocardiogram is equivocal.
Cardiac catheterization with selective left ventriculography and
is not usually required before surgery
In neonates with severe coarctation of the aorta
1.prostaglandin E1 infusion
2. surgical repair→ Once a diagnosis has been confirmed
and the patient stabilized
Older infants with heart failure but good perfusion
Surgical repair should be as soon as possible because
delay lead to less successful operation because of
decreased left ventricular function and degenerative
changes in the aortic wall.