Transcript Congenital Heart Defects Left-to-Right Shunt Lesions by Prof Dr

Congenital Heart Defects
Left-to-Right Shunt Lesions
by
Prof Dr AMR MEGAHED
Left-to-Right Shunt Lesions
• Left-to-right shunt lesions such as
atrial septal defect (ASD), ventricular
septal defect (VSD), patent ductus
arteriosus (PDA)
• Congenital Heart Disease
• Congenital heart disease is a type of defect or
malformation in one or more structures of the
heart or blood vessels that occurs before birth.
• These defects occur while the fetus is
developing in the uterus and affect 8-10 out of
every 1,000 children.
• Congenital heart defects may produce
symptoms at birth, during childhood, and
sometimes not until adulthood.
• What Causes Congenital Heart Disease?
• In the majority of people, the cause of congenital heart
disease is unknown. However, there are some factors
that are associated with an increased chance of getting
congenital heart disease. These risk factors include:
• Genetic or chromosomal abnormalities in the child such
as Down syndrome.
• Taking certain medications or alcohol or drug abuse
during pregnancy.
• Maternal viral infection, such as rubella (German
measles) in the first trimester of pregnancy.
• The risk of having a child with congenital
heart disease is higher if a parent or a
sibling has a congenital heart defect -- the
risk increases from eight in 1,000 to 16 in
1,000.
Left-to-Right Shunt Lesions
Atrial Septal Defect
ASD (ostium secundum defect) occurs as an isolated
anomaly in 5 % to 10% of all congenital heart
defects. It is more common in females than in males
(male/female ratio of 1:2).
Types of ASDs exist:
Secundum defect
Primum defect
Left-to-Right Shunt Lesions
• Ostium secundum defect is the most
common type of ASD, accounting for 50%
to 70% of all ASDs.
• Ostium primum defects occur in about
30% of all ASDs
Left-to-Right Shunt Lesions
Left-to-Right Shunt Lesions
• CLINICAL MANIFESTATIONS :
• History.:
• Infants and children with ASDs are usually
asymptomatic
• Physical Examination
• A widely split and fixed S2 and a grade 2 to 3/6
systolic ejection murmur are characteristic
findings of ASD in older infants and children.
With a large left-to-right shunt, a mid-diastolic
rumble resulting from relative tricuspid stenosis
may be audible at the lower left sternal border.
Left-to-Right Shunt Lesions
• Electrocardiography
• Right axis deviation of +90 to +180
degrees and mild right ventricular
hypertrophy (RVH) or right bundle branch
block (RBBB) with an rsR' pattern in V1
are typical findings. In about 50% of the
patients with sinus venosus ASD, the P
axis is less than 30 degrees.
Left-to-Right Shunt Lesions
Left-to-Right Shunt Lesions
• X-ray Studies :
• Cardiomegaly with enlargement of the RA
and right ventricle (RV) may be present.
• 2. A prominent pulmonary artery (PA)
segment and increased pulmonary
vascular markings are seen when the
shunt is significant.
Left-to-Right Shunt Lesions
• Echocardiography
• MANAGEMENT
• Medical
1. Exercise restriction is unnecessary.
2. Prophylaxis for infective endocarditis is not indicated
unless the patient has associated MVP or other
associated defects. Prophylaxis is indicated in patients
with primum ASD.
3. In infants with CHF, medical management is
recommended because of its high success rate and the
possibility of spontaneous closure of the defect.
Left-to-Right Shunt Lesions
• Nonsurgical closure using a
catheter-delivered closure device
• Surgical Closure
Left-to-Right Shunt Lesions
Ventricular Septal Defect
VSD is the most common form of congenital
heart defect and accounts for 15% to 20%
of all such defects
PATHOLOGY :
The ventricular septum may be divided into
a small membranous portion and a large
muscular portion
Left-to-Right Shunt Lesions
• The defects vary in size, ranging from tiny
defects without hemodynamic significance
to large defects with accompanying CHF
and pulmonary hypertension.
• CLINICAL MANIFESTATIONS
• With a small VSD, the patient is
asymptomatic with normal growth and
development
Left-to-Right Shunt Lesions
• With a moderate to large VSD, delayed
growth and development, decreased
exercise tolerance, repeated pulmonary
infections, and CHF are relatively common
during infancy.
• With long-standing pulmonary
hypertension, a history of cyanosis and a
decreased level of activity may be present.
Left-to-Right Shunt Lesions
• A systolic thrill may be present at the lower left
sternal border. Precordial bulge and
hyperactivity are present with a large-shunt
VSD.
• The intensity of the P2 is normal with a small
shunt and moderately increased with a large
shunt. The S2 is loud and single in patients with
pulmonary hypertension or pulmonary vascular
obstructive disease. A grade 2 to 5/6 regurgitant
systolic murmur is audible at the lower left
sternal border
Left-to-Right Shunt Lesions
• Electrocardiography
• With a small VSD, the ECG is normal.
• With a moderate VSD, left ventricular
hypertrophy (LVH) and occasional left
atrial hypertrophy (LAH) may be seen
• With a large defect, the ECG shows
biventricular hypertrophy (BVH) with or
without LAH
Left-to-Right Shunt Lesions
• X-ray Studies
• Cardiomegaly of varying degrees is
present and involves the LA, left ventricle
(LV), and sometimes RV. Pulmonary
vascular markings increase. The degree of
cardiomegaly and the increase in
pulmonary vascular markings directly
relate to the magnitude of the left-to-right
shunt.
Left-to-Right Shunt Lesions
Left-to-Right Shunt Lesions
• Echocardiography.
• Management
• Treatment of CHF, if it develops, is
indicated with digoxin and diuretics for 2
to 4 months to see if growth failure can be
improved.
• Surgical
Left-to-Right Shunt Lesions
Patent Ductus Arteriosus
PDA occurs in 5% to 10% of all congenital
heart defects, excluding premature infants.
It is more common in females than in
males (male/female ratio of 1:3). PDA is a
common problem in premature infants
Left-to-Right Shunt Lesions
• PATHOLOGY :
• There is a persistent patency of a normal
fetal structure between the left PA and the
descending aorta, that is, about 5 to 10
mm distal to the origin of the left
subclavian artery
Left-to-Right Shunt Lesions
• CLINICAL MANIFESTATIONS
• Patients are usually asymptomatic when
the ductus is small
• A large-shunt PDA may cause a lower
respiratory tract infection, atelectasis, and
CHF (accompanied by tachypnea and
poor weight gain).
Left-to-Right Shunt Lesions
• Physical Examination
• Tachycardia and tachypnea may be present in
infants with CHF
• Bounding peripheral pulses with wide pulse
pressure
• The precordium is hyperactive. A systolic thrill
may be present at the upper left sternal border.
The P2 is usually normal, but its intensity may
be accentuated if pulmonary hypertension is
present. A grade 1 to 4/6 continuous
(“machinery”) murmur is best audible at the left
infraclavicular area or upper left sternal border
Left-to-Right Shunt Lesions
• Electrocardiography.
• The ECG findings in PDA are similar to
those in VSD. A normal ECG or LVH is
seen with small to moderate PDA. BVH is
seen with large PDA. If pulmonary
vascular obstructive disease develops,
RVH is present
Left-to-Right Shunt Lesions
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X-ray findings are also similar to those of VSD.
Echocardiography
MANAGEMENT
Medical
Indomethacin is ineffective in term infants
with PDA and should not be used.
• Standard anticongestive measures with digoxin
and diuretics are indicated when CHF develops
TOF