Congenital Heart Disease
Part I
By
Katrice L. Herndon, M.D.
Acyanotic Congenital Heart Disease
Left-to-Right Shunt Lesions
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Atrial Septal Defect (ASD)
Ventricular Septal Defect (VSD)
Atrioventricular Septal Defect (AV Canal)
Patent Ductus Arteriosus (PDA)
Atrial Septal Defect
• ASD is an opening in the atrial septum
permitting free communication of blood
between the atria. Seen in 10% of all CHD.
Atrial Septal Defect
• There are 3 major types:
• Secundum ASD – at the Fossa Ovalis, most
common.
• Primum ASD – lower in position & is a form of
ASVD, MV cleft.
• Sinus Venosus ASD – high in the atrial septum,
associated w/partial anomalous venous return &
the least common.
Atrial Septal Defect
• Secundum ASD
• Sinus Venosus ASD
Atrial Septal Defect
Clinical Signs & Symptoms
• Rarely presents with signs of CHF or other
cardiovascular symptoms.
• Most are asymptomatic but may have easy fatigability
or mild growth failure.
• Cyanosis does not occur unless pulmonary HTN is
present.
Atrial Septal Defect
Clinical Signs & Symptoms
• Hyperactive precordium, RV heave, fixed widely
split S2.
• II-III/VI systolic ejection murmur @ LSB.
• Mid-diastolic murmur heard over LLSB.
Atrial Septal Defect
• Question:
What causes the systolic & diastolic murmurs of ASD?
• Answer:
Systolic murmur is caused by increased flow across the
pulmonary valve, NOT THE ASD.
Diastolic murmur is caused by increased flow across the
tricupsid valve & this suggest high flow Qp:Qs is 2:1.
Atrial Septal Defect
Treatment:
• Surgical or catherization laboratory closure
is generally recommended for secundum
ASD w/ a Qp:Qs ratio >2:1.
• Closure is performed electively between
ages 2 & 5 yrs to avoid late complications.
• Surgical correction is done earlier in
children w/ CHF or significant Pulm HTN.
Atrial Septal Defect
Treatment
• Once pulmonary HTN w/ shunt reversal
occurs this is considered too late.
• Mortality is < 1%.
Atrial Septal Defect
• Question:
Is endocarditis prophylaxis required for
ASD?
• Answer:
NO
Ventricular Septal Defect
• VSD – is an abnormal opening in the
ventricular septum, which allows free
communication between the Rt & Lt
ventricles. Accounts for 25% of CHD.
Ventricular Septal Defect
• 4 Types
• Perimembranous (or membranous) – Most
common.
• Infundibular (subpulmonary or supracristal VSD)
– involves the RV outflow tract.
• Muscular VSD – can be single or multiple.
• AVSD – inlet VSD, almost always involves AV
valvular abnormalities.
Ventricular Septal Defect
Hemodynamics
• The left to right shunt occurs secondary to PVR
being < SVR, not the higher pressure in the LV.
• This leads to elevated RV & pulmonary pressures
& volume hypertrophy of the LA & LV.
Ventricular Septal Defect
Clinical Signs & Symptoms
• Small - moderate VSD, 3-6mm, are usually
asymptomatic and 50% will close spontaneously
by age 2yrs.
• Moderate – large VSD, almost always have
symptoms and will require surgical repair.
Ventricular Septal Defect
Clinical Signs & Symptoms
• II-III/VI harsh holosystolic murmur heard along the LSB,
more prominent with small VSD, maybe absent with a
very Large VSD.
• Prominent P2, Diastolic murmur.
• CHF, FTT, Respiratory infections, exercise intolerance
hyperactive precordium. Symptoms develop between 1 – 6
months
Ventricular Septal Defect
Treatment
• Small VSD - no surgical intervention, no
physical restrictions, just reassurance and
periodic follow-up and endocarditis prophylaxis.
• Symptomatic VSD - Medical treatment
initially with afterload reducers & diuretics.
Ventricular Septal Defect
Treatment
• Indications for Surgical Closure:
• Large VSD w/ medically uncontrolled symptomatology &
continued FTT.
• Ages 6-12 mo w/ large VSD & Pulm. HTN
• Age > 24 mo w/ Qp:Qs ratio > 2:1.
• Supracristal VSD of any size, secondary to risk of
developing AV insufficiency.
Atrioventricular Septal Defect
• AVSD results from incomplete fusion the
the endocardial cushions, which help to
form the lower portion of the atrial septum,
the membranous portion of the ventricular
septum and the septal leaflets of the
triscupid and mitral valves.
• They account for 4% OF ALL CHD.
Atrioventricular Septal Defect
• Question:
What genetic disease is AVSD more
commonly seen in?
• Answer:
Down’s Syndrome (Trisomy 21), Seen in
20-25% of cases.
Atrioventricular Septal Defect
Complete Form
Incomplete Form
• Low primum ASD
continuous with a posterior
VSD.
• Any one of the
components may be
present.
• Cleft in both septal leaflets
of TV/MV.
• Most common is primum
ASD, cleft in the MV &
small VSD.
• Results in a large L to R
shunt at both levels.
• TR/MR, Pulm HTN w/
increase in PVR.
• Hemodynamics are
dependent on the lesions.
Atrioventricular Septal Defect
• Complete AVSD
Atrioventricular Septal Defect
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Clinical Signs & Symptoms
Incomplete AVSD maybe indistinguishable from
ASD - usually asymptomatic.
Congestive heart failure in infancy.
Recurrent pulmonary infections.
Failure to thrive.
Exercise intolerance, easy fatigability.
Late cyanosis from pulmonary vascular disease w/
R to L shunt.
Atrioventricular Septal Defect
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Clinical Signs & Symptoms
Hyperactive precordium
Normal or accentuated 1st hrt sound
Wide, fixed splitting of S2
Pulmonary systolic ejection murmur w/thrill
Holosystolic murmur @ apex w/radiation to axilla
Mid-diastolic rumbling murmur @ LSB
Marked cardiac enlargement on CX-Ray
Atrioventricular Septal Defect
Treatment
• Surgery is always required.
• Treat congestive symptoms.
• Pulmonary banding maybe required in premature
infants or infants < 5 kg.
• Correction is done during infancy to avoid
irreversible pulmonary vascular disease.
• Mortality low w/incomplete 1-2% & as high as
5% with complete AVSD.
Patent Ductus Arteriosus
• PDA – Persistence of the normal fetal vessel that
joins the PA to the Aorta.
• Normally closes in the 1st wk of life.
• Accounts for 10% of all CHD, seen in 10% of
other congenital hrt lesions and can often play a
critical role in some lesions.
• Female : Male ratio of 2:1
• Often associated w/ coarctation & VSD.
Patent Ductus Arteriosus
• Question:
What TORCH infection is PDA associated
with?
• Answer:
Rubella
Patent Ductus Arteriosus
Hemodynamics
• As a result of higher aortic pressure, blood shunts
L to R through the ductus from Aorta to PA.
• Extent of the shunt depends on size of the ductus
& PVR:SVR.
• Small PDA, pressures in PA, RV, RA are normal.
Patent Ductus Arteriosus
Hemodynamics
• Large PDA, PA pressures are equal to
systemic pressures. In extreme cases 70%
of CO is shunted through the ductus to
pulmonary circulation.
• Leads to increased pulmonary vascular
disease.
Patent Ductus Arteriosus
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Clinical Signs & Symptoms
Small PDA’s are usually asymptomatic
Large PDA’s can result in symptoms of CHF,
growth restriction, FTT.
Bounding arterial pulses
Widened pulse pressure
Enlarged heart, prominent apical impulse
Classic continuous machinary systolic murmur
Mid-diastolic murmur at the apex
Patent Ductus Arteriosus
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Treatment
Indomethacin, inhibitor of prostaglandin
synthesis can be used in premature infants.
PDA requires surgical or catheter closure.
Closure is required treatment heart failure &
to prevent pulmonary vascular disease.
Usually done by ligation & division or intra
vascular coil.
Mortality is < 1%
Obstructive Heart Lesions
• Pulmonary Stenosis
• Aortic Stenosis
• Coarctation of the Aorta
Pulmonary Stenosis
• Pulmonary Stenosis is obstruction in the region
of either the pulmonary valve or the subpulmonary
ventricular outflow tract.
• Accounts for 7-10% of all CHD.
• Most cases are isolated lesions
• Maybe biscuspid or fusion of 2 or more leaflets.
• Can present w/or w/o an intact ventricular septum.
Pulmonary Stenosis
• Question:
What syndrome is PS associated with?
• Answer:
Noonan’s Syndrome, secondary to valve
dysplasia.
Pulmonary Stenosis
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Hemodynamics
RV pressure hypertrophy  RV failure.
RV pressures maybe > systemic pressure.
Post-stenotic dilation of main PA.
W/intact septum & severe stenosis  R-L
shunt through PFO  cyanosis.
Cyanosis is indicative of Critical PS.
Pulmonary Stenosis
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Clinical Signs & Symptoms
Depends on the severity of obstruction.
Asymptomatic w/ mild PS < 30mmHg.
Mod-severe: 30-60mmHg, > 60mmHg
Prominent jugular a-wave, RV lift
Split 2nd hrt sound w/ a delay
Ejection click, followed by systolic murmur.
Heart failure & cyanosis seen in severe cases.
Pulmonary Stenosis
Treatment
• Mild PS no intervention required, close follow-up.
• Mod-severe – require relieve of stenosis.
• Balloon valvuloplasty, treatment of choice.
• Surgical valvotomy is also a consideration.
Aortic Stenosis
• Aortic Stenosis is an obstruction to the outflow
from the left ventricle at or near the aortic valve
that causes a systolic pressure gradient of more
than 10mmHg. Accounts for 7% of CHD.
• 3 Types
• Valvular – Most common.
• Subvalvular(subaortic) – involves the left outflow
tract.
• Supravalvular – involves the ascending aorta is
the least common.
Aortic Stenosis
• Question:
Which syndrome is supravalvular stenosis
found in?
• Answer:
Williams Syndrome
Aortic Stenosis
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Hemodynamics
Pressure hypertrophy of the LV and LA with
obstruction to flow from the LV.
Mild AS
0-25mmHG
Moderate AS
25-50mmHg
Severe AS
50-75mmHg
Critical AS
> 75mmHg
Aortic Stenosis
Clinical Signs & Symptoms
• Mild AS may present with exercise intolerance,
easy fatigabiltity, but usually asymptomatic.
• Moderate AS – Chest pain, dypsnea on exertion,
dizziness & syncope.
• Severe AS – Weak pulses, left sided heart failure,
Sudden Death.
Aortic Stenosis
Clinical Signs & Symptoms
• LV thrust at the Apex.
• Systolic thrill @ rt base/suprasternal notch.
• Ejection click, III-IV/VI systolic murmur @
RSB/LSB w/ radiation to the carotids.
Aortic Stenosis
Treatment
• Because surgery does not offer a cure it is reserved
for patients with symptoms and a resting gradient
of 60-80mmHg.
• For subaortic stenosis it is reserved for gradients
of 40-50mmHg because of it’s rapidly progressive
nature.
• Balloon valvuloplasty is the standard of treatment.
Aortic Stenosis
Treatment
• Aortic insufficiency & re-stenosis is likely after
surgery and may require valve replacement.
• Activity should not be restricted in Mild AS.
• Mod-severe AS, no competitive sports.
Coarctation of the Aorta
• Coarctation- is narrowing of the aorta at varying
points anywhere from the transverse arch to the
iliac bifurcation.
• 98% of coarctations are juxtaductal
• Male: Female ratio 3:1.
• Accounts for 7 % of all CHD.
Coarctation of the Aorta
• Question:
What other heart anomaly is coarctation
associated with?
• Answer:
Bicuspid aortic valve, seen in > 70% of
cases.
Coarctation of the Aorta
• Question:
What genetic syndrome is coarctation seen
in?
• Answer:
Turner’s Syndrome
Coarctation of the Aorta
Hemodynamics
• Obstruction of left ventricular outflow 
pressure hypertrophy of the LV.
Coarctation of the Aorta
Clinical Signs & Symptoms
• Classic signs of coarctation are diminution or
absence of femoral pulses.
• Higher BP in the upper extremities as compared to
the lower extremities.
• 90% have systolic hypertension of the upper
extremities.
• Pulse discrepancy between rt & lt arms.
Coarctation of the Aorta
Clinical Signs & Symptoms
• With severe coarc. LE hypoperfusion, acidosis,
HF and shock.
• Differential cyanosis if ductus is still open
• II/VI systolic ejection murmur @ LSB.
• Cardiomegaly, rib notching on X-ray.
Coarctation of the Aorta
Coarctation of the Aorta
Treatment
• With severe coarctation maintaining the ductus
with prostaglandin E is essential.
• Surgical intervention, to prevent LV dysfunction.
• Angioplasty is used by some centers.
• Re-coarctation can occur, balloon angioplasty is
the procedure of choice.
Questions
Examination of a 3-hr old infant reveals
dysmorphic features and cyanosis. Both the
occiput and facial profile are flat, and the
fontanelle is abnormally enlarged. The space
between the great and second toe is wide, and
there is a palmar crease extending across the
left palm. Room air oximetry reveals a saturation
70%.
Questions
Of the following, the MOST likely lesion to
be found on echocardiography would be
A. Atrioventricular septal defect
B. Coarctation of the aorta
C. Hypoplastic left heart
D. Total anomalous pulmonary venous return
E. Truncus arteriosus
Questions
After a few days of poor feeding and
tachypnea, a 3 week old presents with
hypotension, poor central and peripheral
pulses, and severe metabolic acidosis. A
gallop is audible, and the heart appears
enlarged on chest radiography. Hepatomegaly
is marked.
Questions
Of the following, the BEST intervention to
produce a sustained improvement is
A. 100% Oxygen administration
B. Dopamine infusion
C. Gamma globulin infusion
D. Phenylephrine infusion
E. Prostaglandin E infusion
Questions
A term infant is born with a large ventricular septal
defect. At what age is the infant most likely to first
demonstrate clinical findings of CHF
A. 2 days
B. 2 weeks
C. 2 months
D. 6 months
E. 12 months