ETIOLOGY AND EPIDEMIOLOGY Congenital heart disease occurs in 8 per 1,000 births. The spectrum of lesions ranges from asymptomatic to fatal. Although most cases of congenital heart disease are multifactorial, some lesions are associated with chromosomal disorders, single gene defects, teratogens, or maternal metabolic disease (see Table139-2). Congenital heart defects can be divided into three pathophysiological groups (Table 143.1). 1. Left-to-right shunts 2. Right-to-left shunts 3. Obstructive, stenotic lesions Acyanotic congenital heart disease includes left-to-right shunts resulting in an increase in pulmonary blood flow (patent ductus arteriosus [PDA], ventricular septal defect [VSD], atrial septal defect [ASD]) and obstructive lesions (aortic stenosis, pulmonary stenosis, coarctation of the aorta), which usually have normal pulmonary blood flow. VENTRICULAR SEPTAL DEFECTEtiology and Epidemiology The ventricular septum is a complex structure that can be divided into four components. The largest component is the muscular septum. The inlet or posterior septum comprises endocardial cushion tissue. The subarterial or supracristal septum com prises conotruncal tissue. The membranous septum is below the aortic valve and is relatively small. VSDs occur when any of these components fail to develop normally (Fig. 143.1). VSD, the most common congenital heart defect, accounts for 25% of all congenital heart disease. Perimembranous VSD

1. PRESENTER: MISHECK NKOWANI
7TH YEAR
MODERATOR : DR FISEKO
ACYANOTIC DISEASE
CONGENITAL HEART
DISEASE

2. CHD occur during the 1st 8 wks. of fetal development
Most congenital defects are well tolerated during fetal life.
Incidence
• 8/1000 live births
• 3-4/100 still born
• 2/100 premature infants excluding PDA
These are the most common birth defects
ETIOLOGY
 Generally considered to be caused by factors that are usually both genetic and
environmental, where a combination of genes from both parents, in addition to
unknown environmental factors, produce the trait or condition.
 Such as maternal risk factors
• seizure disorders or intake of anti-seizure medications
• intake of lithium for depression
• Lupus

3. Chromosome abnormalities:
5 to 8 % of all babies with CHD have a chromosome abnormality includes
• Down syndrome,
• trisomy 18 and trisomy 13, Turner’s syndrome,
• Cri-du-chat syndrome
Family History:
• risk increases when either parent has CHD, or when another sibling was born with CHD
• If you have had one child with CHD, the chance that another child will be born with CHD
ranges from 1.5 to 5 %, depending on the type of CHD in the first child.
• If you have had two children with CHD, then the risk increase to 5 to 10 %, to have another
child with CHD.
• If the mother has CHD, the risk for a child to be born with CHD ranges from 2.5 to 18
percent, with an average risk of 6.7 percent.

4. FETAL CIRCULATION

5. VENTRICULAR SEPTAL DEFECT
Etiology and Epidemiology
The ventricular septum is a complex structure that can be divided into four
components. The largest component is the muscular septum. The inlet or posterior
septum comprises endocardial cushion tissue. The subarterial or supracristal septum
comprises conotruncal tissue. The membranous septum is below the aortic valve and
is relatively small. VSDs occur when any of these components fails to develop
normally VSD, the most common congenital heart defect, accounts for 25% of all
congenital heart disease. Perimembranous VSDs are the most common of all VSDs
(67%). Although the location of the VSD is important prognostically and in
approach to repair, the amount of flow crossing a VSD depends on the size of the
defect and the pulmonary vascular resistance. Large VSDs are not symptomatic at
birth because the pulmonary vascular resistance is normally elevated at this time. As
the pulmonary vascular resistance decreases over the first 6 to 8 weeks of life, the
amount of shunt increases, and symptoms may develop.
Clinical Manifestations
Small VSDs with little shunt are often asymptomatic but have a loud murmur.
Moderate to large VSDs result in pulmonary

7. overcirculation and heart failure. The typical physical finding with a VSD is a
pansystolic murmur, usually heard best at the lower left sternal border. There may be
a thrill. Large shunts increase flow across the mitral valve causing a mid-diastolic
murmur at the apex. The splitting of S2 and intensity of P2 depend on the pulmonary
artery pressure
. Imaging Studies
Electrocardiogram (ECG) and chest x-ray findings depend on the size of the VSD.
Small VSDs usually have normal studies. Larger VSDs cause volume overload to the
left side of the heart, resulting in ECG findings of left atrial and ventricular
enlargement and hypertrophy. A chest x-ray may reveal cardiomegaly, enlargement
of the left ventricle, an increase in the pulmonary artery silhouette, and increased
pulmonary blood flow. Pulmonary hypertension due to either increased flow or
increased pulmonary vascular resistance may lead to right ventricular enlargement
and hypertrophy.
Treatment
Approximately one third of all VSDs close spontaneously. Small VSDs usually close
spontaneously and, if they do not require surgery
• Prophylactic antibiotics to prevent bacterial endocarditis
• Surgical repair – VSD will be closed with stitches or special patch

8. ATRIAL SEPTAL DEFECT
Etiology and Epidemiology
During the embryologic development of the heart, a septum grows toward
the endocardial cushions to divide the atria. Failure of septal growth or
excessive reabsorption of tissue leads to ASDs. ASDs represent
approximately 10% of all congenital heart defects. A secundum defect,
with the hole in the region of the foramen ovale, is the most common
ASD. A primum ASD, located near the endocardial cushions, may be part
of a complete atrioventricular canal defect or may be present with an
intact ventricular septum. The least common ASD is the sinus venosus
defect, which may be associated with anomalous pulmonary venous return.
Clinical Manifestations
The pathophysiology and amount of shunting depend on the size of the
defect and the relative compliance of the both ventricles. Even with large
ASDs and significant shunts, infants and children are rarely symptomatic.
A prominent right ventricular impulse at the left lower sternal border
(LLSB) often can be palpated. A soft (grade I or II) systolic ejection
murmur in the region of the right ventricular outflow tract and a fixed split
S2 (due to overload of the right ventricle with prolonged ejection into the
pulmonary circuit) are often audible. A larger shunt may result in a mid-
diastolic murmur at the LLSB as a result of the increased volume passing
across the tricuspid valve.

10. SIGNS AND SYMPTOMS
• infant tires easily when feeding
• fatigue
• sweating
• tachypnea, tachycardia
• shortness of breath, crackles
• poor growth
• murmur

11. Imaging Studies
ECG and chest x-ray findings reflect the increased blood flow through the
right atrium, right ventricle, pulmonary arteries, and lungs. The ECG may
show right axis deviation and right ventricular enlargement. A chest
radiograph may show cardiomegaly, right atrial enlargement, and a prominent
pulmonary artery.
Treatment
Medical management is rarely indicated. If a significant shunt is still present
at around 3 years of age, closure is usually recommended. Many secundum
ASDs can be closed with an ASD closure device in the catheterization
laboratory. Primum and sinus venosus defects require surgical closure

12. PATENT DUCTUS ARTERIOSUS
Etiology and Epidemiology
The ductus arteriosus allows blood to flow from the pulmonary artery to the aorta
during fetal life. Failure of the normal closure of this vessel results in a PDA With a
falling pulmonary vascular resistance after birth, left-to-right shunting of blood and
increased pulmonary blood flow occur. Excluding premature infants, PDAs
represent approximately 5% to 10% of congenital heart disease.
Clinical Manifestations
Symptoms depend on the amount of pulmonary blood flow. The magnitude of the
shunt depends on the size of the PDA (diameter, length, and tortuosity) and the
pulmonary vascular resistance. Small PDAs are asymptomatic; moderate to large
shunts can produce the symptoms of heart failure as the pulmonary vascular
resistance decreases. The physical examination findings depend on the size of the
shunt. A widened pulse pressure is often present as a result of the runoff of blood
into the pulmonary circulation during diastole. A continuous, machine-like murmur
can be heard at the left infraclavicular area, radiating along the pulmonary arteries
and often well heard over the left side of the back. Larger shunts with increased
flow across the mitral valve mayresult in a mid-diastolic murmur at the apex and a
hyperdynamic precordium. Splitting of S2 and intensity of P2 depend on the
pulmonary artery pressure A thrill may be palpable.

13. .
Imaging Studies
ECG and chest x-ray findings are normal with small PDAs. Moderate to large
shunts may result in a full pulmonary artery silhouette and increased pulmonary
vascularity. ECG findings vary from normal to evidence of left ventricular
hypertrophy. If pulmonary hypertension is present, there is also right ventricular
hypertrophy.
Treatment
Spontaneous closure of a PDA after a few weeks of age is uncommon in full-term
infants. Moderate and large PDAs may be managed initially with diuretics, but
eventually require closure. Elective closure of small, hemodynamically insignificant
PDAs is controversial. Most PDAs can be closed in the catheterization laboratory by
either coil embolization or a PDA closure device

14. ENDOCARDIAL CUSHION DEFECT
Etiology and Epidemiology
Endocardial cushion defects, also referred to as atrioventricular canal defects,
may be complete or partial Failure of the septum to fuse with the endocardial
cushion results in abnormal atrioventricular valves as well. The complete defect
results in a primum ASD, a posterior or inlet VSD, and clefts in the anterior
leaflet of the mitral and septal leaflet of the tricuspid valves. In addition to left-to-
right shunting at both levels, there may be atrioventricular valve insufficiency.
Clinical Manifestations
The symptoms of heart failure usually develop as the pulmonary vascular
resistance decreases over the first 6 to 8 weeks of life. Symptoms may be earlier
and more severe with significant

15. atrioventricular valve insufficiency. Pulmonary hypertension resulting from
increased pulmonary circulation often develops early. The presence of murmurs
varies depending on the amount of shunting at both atrial and ventricular levels. If
there is a large VSD component, S2 will be single. Growth is usually poor.
Complete endocardial cushion defects are most commonly seen in children with
Down syndrome.
Imaging Tests
The diagnosis usually is made with echocardiography. A chest radiograph reveals
cardiomegaly with enlargement of all chambers and the presence of increased
vascularity. An ECG reveals left axis deviation and combined ventricular
hypertrophy and may show combined atrial enlargement.
Treatment
Initial management includes diuretics such as
and afterload reduction for treatment of heart failure. Surgical repair of the defect
ultimately is required

16. PULMONARY STENOSIS
Etiology
Pulmonary stenosis accounts for approximately 10% of all congenital heart disease
and can be valvular, subvalvular, or supravalvular in nature. Pulmonary stenosis
results from the failure of the development, in early gestation, of the three leaflets of
the valve, insufficient resorption of infundibular tissue, or insufficient canalization
of the peripheral pulmonary arteries.
Clinical Manifestations
Symptoms depend on the degree of obstruction present. Mild pulmonary stenosis is
asymptomatic. Moderate to severe stenosis results in exertional dyspnea and easy
fatigability. Newborns with severe stenosis may be more symptomatic and even
cyanotic because of right-to-left shunting at the atrial level. Pulmonary stenosis
causes a systolic ejection murmur at the second left intercostal space which radiates
to the back. A thrill may be present. S2 may be widely split with a quiet pulmonary
component. With more severe pulmonary stenosis, an impulse at the lower left
sternal border results from right ventricular hypertrophy. Valvular stenosis may
result in a click that varies with respiration. Worsening stenosis causes an increase in
the duration of the murmur and a higher frequency of the sound. The systolic
ejection murmurs of peripheral pulmonary stenosis are heard distal to the site of
obstruction in the pulmonary circulation, including radiation to the back

17. Imaging Tests
ECG and chest x-ray findings are normal in mild stenosis. Moderate to severe
stenosis results in right axis deviation and right ventricular hypertrophy. The heart
size is usually normal on chest x-ray, although dilation of the main pulmonary
artery may be seen. Echocardiography provides assessment of the site of stenosis,
degree of hypertrophy, and valve morphology, as well as an estimate of the
pressure gradient
Treatment
Valvular pulmonary stenosis usually does not progress, especially if it is mild.
Balloon valvuloplasty is usually successful in reducing the gradient to acceptable
levels for more significant or symptomatic stenosis. Surgical repair is required if
balloon valvuloplasty is unsuccessful or when subvalvular (muscular) stenosis is
present

18. Narrowing of the aorta
can occur anywhere, but is most likely to happen in the segment just after the aortic
arch. This narrowing restricts the amount of blood to the lower part of the body
occurs in about 8-11 % of all children with CHD
COARCTATION OF THE AORTA

19. Imaging Studies
The ECG and chest x-ray show evidence of right ventricular enlargement and
hypertrophy in infantile coarctation with marked cardiomegaly and pulmonary
edema. 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. Rib notching may also be seen in older children (>8
years of age) with large collaterals. Echocardiography shows the site and degree of
coarctation, presence of left ventricular hypertrophy, and aortic valve morphology
and function.
Treatment
Management of an infant presenting with cardiac decompensation includes
intravenous infusion of prostaglandin E1 (chemically opens the ductus arteriosus),
• inotropic agents,
• diuretics,
• supportive care. Balloon angioplasty has been done, especially in critically ill
infants, but surgical repair of the coarctation is most commonly performed.
Ballooning and stenting of older patients with coarctation has become more
accepted as primary therapy, but surgical repair remains a common form of
management