Congenital Heart Disease

Prevalence
O 6-8 per 1000 live births, 25% are life threatening
and require early intervention.
Congenital cardiac defects have wide spectrum
of severity in infant;
 appr. 2-3 in 1000 newborn infants will be
symptomatic with heart disease in the 1st year of
life.
 Diagnosis is established by 1 wk of age in 40-50%
of patients
 By 1month of age in 50-60% patients.

Circulatory Adjustment at Birth
O Main event after birth:
 Clamping of umbilical cord results in sudden
increase in systemic vascular resistance.
 Sudden expansion of lungs with the first few
breaths

Result Of Pressure Changes After Birth
 Closure of foramen ovale.
 Constriction and closure of
ductus arteriosus and ductus
venosus.

Hemodynamic Classification Of Congenital
Heart Disease
Acyanotic Congenital
Heart Disease
Cyanotic Congenital
Heart Disease
 Lesions resulting in
increased volume
overload.
 Lesions resulting in
increased pressure
load.
 Cyanotic lesions with
decreased pulmonary
blood flow.
 Cyanotic lesions with
increased pulmonary
blood flow.

Left to Right Shunt
• ASD
• VSD
• Aortopulmonary window
• Patent ductus
Obstructive Lesions
• Obstructive lesions of the mitral
valve.
• Pulmonary valve stenosis
• Valvar aortic stenosis
• Coarctation of aorta
• Congenital mitral and tricuspid
valve regurgitation

Lesions resulting in increased volume
overload
O Most common: lesion causing left to right shunting.
e.g. ASD, VSD, atrioventricular septal defect, PDA
O Common denominator in this group is the
presence of communication between the systemic
and pulmonary sides of the circulation.

Communication between systemic and pulmonary
sides of communication
Shunting of fully oxygenated blood back to lungs
Direction and magnitude of the shunt across
such communication depend on:
 Size of the defect
 Relative pulmonary and systemic pressure.
 Vascular resistance.
 Compliance of the two chambers connected
by defect.

Increased volume of blood in the lungs
Decrease in pulmonary compliance and
increase in work of breathing.
Fluid leaks into the interstitial space and alveoli
pulmonary edema
Development of symptoms of heart failure; tachypnea,
tachycardia, sweating, chest retractions, nasal flaring &
wheezing.

Lesions Resulting In Increased Pressure Load
O Major cause is obstruction to normal blood flow.
O Most frequent are obstruction to ventricular
outflow: valvular pulmonic stenosis, valvular aortic
stenosis, and coartation of aorta.

Clinical Approach To Infant And Children With
Cyanotic Congenital Heart Disease.
O Recognizable Cyanosis is due to a reduced Hb
content of more than 4-6mg/dl capillary blood.
O Situation seems different in anemic children.
O Saturation below 85% is required to produce
clinical cyanosis.

Central Cyanosis: A clue to congenital Heart
Disease
O Due to right to left shunting either intracardiac or
extracardiac.
O Cyanosis in cyanotic CHD is often uniform and
constant.
O Occasionally differential cyanosis can occur- upper
limbs are pink and lower limbs are blue and vice-
versa.

Potential Pitfalls In Clinical Recognition Of Congenital
Cyanotic Heart Disease
O Clinical assessment of cyanosis can be inaccurate
depending upon Hb status.
O Some acyanotic CHD, especially large left to right
shunts can develop severe chest infection and
CHF and cause central cyanosis.
O Primary lung conditions can mimic cyanotic heart
disease.

Classification of CCHD
Decreased Pulmonary
Blood Flow
Increased Pulmonary
Blood Flow
 With Pulmonic stenosis.
 With Pulmonary
hypertension
( both effectively reduce blood
flow across lungs and cause
central cyanosis)
There is a Rt to Lt intracardiac
shunt at some level.
 Transposition of great
arteries, tricuspid atresia,
Pulmonary atresia with
intact IVS, TAPVC

Clinical Features
O Cyanosis
O Difficult in feeding
O Excessive sweating involving forehead or
occiput
O Poor Growth
O Difficult breathing
O Frequent respiratory infections
O Specific Syndromes

O Specific Syndromes:
 Trisomy 21 : most common
 Trisomy 13 & 18
 Turner syndrome

Nadas Criteria
O Used to assess presence of CHD.
O Presence of one major and two minor criteria is
essential for the presence of heart disease.
Major Minor
Systolic murmur grade III
or more
Systolic murmur grade I or
II abnormal 2nd heart sound
Diastolic murmur Abnormal ECG
Cyanosis Abnormal X-ray
CCF Abnormal Blood pressure

Imaging Studies
O Echocardiography
O Cardiac magnetic resonance imaging: it is important for
evaluation of CHD, especially in older patients and for
postoperative evaluation. MRI also defines extracardiac
structures such as branch pulmonary arteries,
pulmonary veins and aortopulmonary collaterals.
O Diagnostic cardiac catheterization: the role of diagnostic
cardiac catheterization for patients with CHD has
declined with the availability of high quality
echocardiography, MRI and CT. it is advised if non-
invasive investigations do not provide information that is
required for surgery.

Atrial Septal Defect
O ASD as an isolated anomaly accounts for 5-10% of
all CHD.
O Acyanotic heart disease with left to right shunts is
classified as pretricuspid and post tricuspid shunts.
O The physiology of ASD is that of a pretricuspid
shunt.
O The left to right shunt and the consequent excessive
pulmonary blood flow is dictated by relative stiffness
of two ventricles.

Clinical Manifestations
 Diastolic flow murmur : subtle or even inaudible.
 Ejection systolic murmur.
 The second heart sound splits widely and is fixed.
( delayed P2 )
 PAH is typically absent or at most, mild.
 ECG Findings:
 In Ostium secundum ASD, characterized by right
axis deviation and right ventricular hypertrophy.

O Ostium primum ASD: presence of left axis
deviation beyond -30 degree.
O Chest X Ray:
 mild to moderate cardiomegaly;
 right atrial and right ventricular enlargement,
 prominent main pulmonary artery segment,
 a relatively small aortic shadow and plethoric lung
fields.
 The left atrium does not increase in size in ASD,
unless associated with other anomalies like mitral
regurgitation.

O 2D echo in subcoastal view often best identifies
the defect.
O The echocardiogram allows decision regarding
suitability of catheter closure, based on
measurements of the defect and the adequacy of
margins.
Assessment Of The Severity
The size of the left to right shunt is directly
proportional to the intensity of the murmurs and heart
size.
The larger the shunt, the more the cardiomegaly and
the louder the pulmonary and tricuspid murmurs.

O Natural History And Complications
 Heart failure is exceptional in infancy.
 A small proportion of patients might develop
pulmonary HTN by the 2nd or 3rd decade.
 Closure of ASD is recommended to prevent
complications of atrial arrhythmias and heart
failure in late adulthood.

Management
O Most fossa ovalis defect can be closed
percutaneously in the catheterization laboratory with
occlusive devices.
O Some may require surgical closure.
O Closure is recommended before school entry to
prevent late complications.
O Small defects (<8mm) can be observed.
O Spontaneous closure is well recognized in small
defects that are diagnosed in infancy or early
childhood.

Ventricular Septal Defect
O Most common congenital cardiac lesions
identified at birth accounting for one-
quarter of all CHD.
O VSD is a communication between the two
ventricles.

Hemodynamics of VSD
O There is shunting of oxygenated blood from the left to
the right ventricle.
O The left ventricle starts contracting before the right
ventricle. The flow of blood from the left to right
ventricle starts early in systole.
O The murmur starts early, masking the first sound and
continues throughout the systole with almost the same
intensity appearing as pansystolic murmur on
auscultation and palpable as a thrill.

O The left to right shunt streams to pulmonary artery
more or less directly.
O This flow of blood across normal pulmonary valve
results in an ejection systolic murmur at the
pulmonary valve.
O Chest X Ray shows pulmonary plethora. The
increased volume of blood finally reaches the left
atrium and may result in left atrial enlargement.
O There is presence of delayed diastolic murmur at the
apex.
O The large flow across the normal mitral valve results
in accentuated first heart sound, not appreciable at
bedside as it is masked by pansystolic murmur.

Clinical features of VSD
O Patient became symptomatic around 6 to 10
weeks of age with CCF
O Premature babies with a VSD can became
symptomatic even earlier.
O Palpitation, dyspnea on exertion & frequent chest
infection : main symptoms in older children.
O The precordium is hyperkinetic with a systolic thrill
at the left sternal border.

O Heart size is moderately enlarged.
O The first and second sounds are masked by a
pansystolic type of murmur at the left sternal
border. Max.intensity of the murmur may be in the
3rd, 4th & 5th left interspace.
O The 2nd sound can be found at 2nd left interspace
or higher.
O It is widely split and variable with accentuated P2.
O A third sound may be audible at the apex.

O ECG:
 Variable in VSD
 Initially all patient with VSD have ventricular hypertrophy.
 In small or normal sized VSD electrocardiogram became
normal.
 In patients with large left to right shunt, without pulmonary
arterial hypertension, the ECG shows left ventricular
hypertrophy by the time they are 6-12 months old.
 In patient with pulmonic stenosis, hypertrophy of both the
ventricles may be seen.

O Chest X-ray: The pulmonary vasculature is
increased. Aorta appears normal or smaller than
normal.
O 2D echo can identify the number, site and size of
defects, presence or absence of pulmonic stenosis
or pulmonary HTN and associated defects.

Assessment of Severity
O When VSD is small:
 Left to right shunt murmur continues to be
pansystolic
 2nd heart sound is normally split and the
intensity of P2 is normal.
 There is also absence of delayed diastolic
mitral murmur.

O When VSD is very small:
 It acts as a stenotic area resulting in an ejection systolic
murmur.
 This is relatively common cause of systolic murmurs in young
infants that disappear because of the spontaneous closure.
O When VSD is large:
 It results in transmission of left ventricular systolic pressure
to the right ventricle.
 The right ventricle pressure increases and the difference
between the two ventricles reduces.
 The systolic left to right shunt murmur becomes shorter and
softer and on the bedside is heard as an ejection systolic
murmur.

O Patient of VSD may have either hyperkinetic or
obstructive pulmonary arterial HTN.
O The P2 is accentuated in both.

O Course & Complications
 Patient with VSD have a very variable course.
 A patient with a small VSD usually remain
asymptomatic throughout life.
 May develop CCF in early infancy, which is
potentially life threatening.
 70% of defects became smaller in size.
 90% of defects have spontaneous closure, it
occurs by the age of 3 years.
 VSD is the commonest congenital lesion
complicated by infective endocarditis

Management
O Control of CCF
O Treatment of Chest infections & treatment od
anemia & infective endocarditis.
O Patient should be followed carefully to assess the
development of pulmonic stenosis, pulmonary
HTN or aortic regurgitation.

O Surgical treatment :
 CCF occurs in early infancy
 Left to right shunt is large
 Associated pulmonic stenosis, pulmonary HTN or
aortic regurgitation.
 Not indicated in patient with small VSD and in
severe Pulmonary arterial HTN.