2. DISCLAIMER:
This lecture is based on generalizations.
In reality, a congenital heart defect (CHD)
can act completely different from one
patient to the next (eg- classic ToF vs
“pink” ToF).
There are many more CHDs than what
I’ve listed and I hope you can use these
principles to help you out with those.
3. Fetal Circulation
For the fetus the placenta is the oxygenator
so the lungs do little work
RV & LV contribute equally to the systemic
circulation and pump against similar
resistance
Shunts are necessary for survival
ductus venosus (bypasses liver)
foramen ovale (R→L atrial level shunt)
ductus arteriosus (R→L arterial level shunt)
4.
5. Transitional Circulation
With first few breaths lungs expand and
serve as the oxygenator (and the placenta
is removed from the circuit)
Foramen ovale functionally closes
Ductus arteriosus usually closes within
first 1-2 days
6. Neonatal Circulation
RV pumps to pulmonary circulation and
LV pumps to systemic circulation
Pulmonary resistance (PVR) is high; so
initially RV pressure ~ LV pressure
By 6 weeks pulmonary resistance drops
and LV becomes dominant
7. Normal Pediatric Circulation
LV pressure is 4-5 x RV pressure (this is
feasible since RV pumps against lower
resistance than LV)
RV is more compliant chamber than LV
8. 100%
90/ No shunts
60 20/8
No pressure gradients
75% 75% 100% Normal AV valves
Normal semilunar
valves
20/ 90/ If this patient was
desaturated what
would you think?
9. If you have a hole in the heart what
affects shunt flow?
1. Pressure – easy enough to understand
2. Resistance – impedance to blood flow
Remember, the LV has higher pressure and
a higher resistive circuit relative to the RV.
Now onto the nitty-gritty …
10. Congenital Heart Disease (CHD)
Occurs in 0.5-1% of all live births
Simple way to classify is:
L→R shunts
Cyanotic CHD (R→L shunts)
Obstructive lesions
11. L→R Shunts (“Acyanotic” CHD)
Defects
1. VSD
2. PDA
3. ASD
4. AVSD (or complete atrioventricular canal)
May not be apparent in neonate due to
high PVR (ie- bidirectional shunt)
12. L→R Shunts – General Points
PDA & VSD ASD
Presents in childhood w/
Presents in infancy w/
murmur or exercise
heart failure, murmur,
intolerance (AVSD or 1o ASD
and poor growth
presents earlier)
Left heart enlargement Right heart enlargement
(LHE)
(RHE)
Transmits flow and Transmits flow only
pressure
AVSD can present as either depending on size of ASD & VSD component
15. Pulm vasc
markings
equal in
upper and
lower zones
Cardiomegaly
16. Eisenmenger’s Syndrome
A long standing L→R shunt will eventually
cause irreversible pulmonary vascular
disease
This occurs sooner in unrepaired VSDs
and PDAs (vs an ASD) because of the
high pressure
Once the PVR gets very high the shunt
reverses (ie- now R→L) and the patient
becomes cyanotic
17. R→L Shunts (CCHD)
• “Blue blood bypasses the lungs”
• Degree of cyanosis varies
• Classify based on pulmonary blood flow (PBF)
↑ PBF ↓ PBF
Truncus arteriosus Tetralogy of Fallot
Total anomalous pulm. Tricuspid atresia
venous return (TAPVR) Ebstein’s anomaly
Transposition of the great
arteries (TGA)
Please note: This is a generalization. In reality most of these defects can present with
low or high PBF (eg- ToF with little PS acts more like a VSD with high PBF)
18. R→L Shunts
↑ PBF
Presents more often
with heart failure
(except TGA)
Pulmonary congestion
worsens as neonatal
PVR lowers
Sats can be 93-94% if
There is unimpeded Equal
there is high PBF
PBF; thus, extreme pressures
pulmonary here too
overcirculation.
19. R→L Shunts
↓ PBF
Presents more often
with cyanosis
See oligemic lung
fields
Closure of PDA may
worsen cyanosis
Dynamic subvalvular
Why are
obstruction here
causes “Tet spells”
pressures
equal?
20. Pulmonary
90% overcirculation Too little
70% PBF
70% 99% 60% 99%
99%
99%
70% 60%
22. Obstructive Lesions
Ductal Dependent Non-Ductal Dependent
1. Critical PS/AS 1. Mild-moderate AS
2. Critical CoA/IAA 2. Mild-moderate CoA
3. HLHS 3. Mild-moderate PS
Presents in CV shock at Presents in older
2-3 days of age when child w/ murmur,
PDA closes
exercise intolerance,
+/- cyanosis or HTN (in CoA)
Needs PGE1 Not cyanotic
23. Ductal-Dependent
Lesion
Without a PDA there is no
blood flow to the abdomen
and lower extremities.
(Blue blood is better than no blood.)
24. Physical Exam
Inspection and palpation
Cardiac cyanosis must be central
Differential cyanosis = R→L PDA shunt
Differential edema/congestion implies
obstruction of SVC or IVC
Increased precordial activity
Displaced PMI
RV heave = RV hypertension
25. Physical exam
Lungs
Respiratoryrate and work of breathing
Oxygen saturations
Abdominal exam
Liver size
Extremities
Perfusion
Edema
Clubbing
26. Physical Exam
Pulses (very important)
Differentialpulses (weak LE) = CoA
Bounding pulse = run-off lesions (L→R PDA
shunt, AI, BT shunt)
Weak pulse = cardiogenic shock or CoA
Pulsus paradoxus is an exaggerated SBP
drop with inspiration → tamponade or bad
asthma
Pulsus alternans – altering pulse strength →
LV mechanical dysfunction
27. Physical Exam
Heart sounds
Ejection click = AS or PS
Mid-systolic click = MVP
Loud S2 = Pulmonary HTN
Single S2 = one semilunar valve (truncus),
anterior aorta (TGA), pulmonary HTN
Fixed, split S2 = ASD, PS
Gallop (S3) – may be due to cardiac
dysfunction/ volume overload
Muffled heart sounds and/or a rub = pericardial
effusion ± tamponade
28. Physical Exam
Types of Murmurs
Systolic Ejection Murmur (SEM) =
turbulence across a semilunar valve
Holosystolic murmur = turbulence begins
with systole (VSD, MR)
Continuous murmur = pressure difference
in systole and diastole (PDA, BT shunt)
29. Innocent murmurs
Peripheral pulmonic stenosis (PPS)
Heard in newborns – disappears by one year
of age (often earlier)
Soft SEM at ULSB w/ radiation to axilla and
back (often heard best in axilla/back)
Need to differentiate b/w PPS and actual
pulmonic stenosis. PS often associated with
a valvular click and heard best over
precordium
30. Innocent murmurs
Still’s murmur
Classic innocent murmur
Heard most commonly in young children (3-5 yrs of
age) but can be heard in all ages
“Vibratory” low-frequency murmur often heard along
LSB and apex
Positional – increases in intensity when pt is in supine
position
Also louder in high output states (i.e. dehydration,
fever)
Need to differentate from VSD
31. Innocent murmurs
Pulmonary flow murmur
Often heard in older children and adolscents
Soft SEM at ULSB, little radiation; normal second
heart sound
Not positional
Need to differentiate b/w mild PS and especially an
ASD
Hint: ASD would have a fixed split second heart sound
32. Innocent murmurs
Venous hum
Often heard in toddlers, young children
Low pitched continuous murmur often heard best in
infraclavicular area, normal heart sounds
Positional – diminishes or goes completely away
when pt in supine position or with compression of
jugular vein
Need to differentiate between a PDA
33. Syndrome Associations
Down – AV canal and VSD
Turner – CoA, AS
Trisomies 13 and 18 – VSD, PDA
Fetal alcohol – L→R shunts, ToF
CHARGE – conotruncal (ToF, truncus)
35. Kawasaki Disease (KD)
Now the #1 cause of acquired heart
disease
A systemic vasculitis (etiology-unknown)
Tests – CBC, CMP, CRP, ESR, EKG,
ECHO
Rx – IVIG at 2g/kg and high-dose ASA
Prognosis – Coronary artery dilatation
in 15-25% w/o IVIG and 4% w/ IVIG (if
given within 10 days of fever onset). Risk
of coronary thrombosis.
36. Kawasaki – Clinical criteria
Fever for at least 5 days AND 4 of the
following 5 criteria:
Eyes - conjunctival injection (ie- no exudate)
Lips & mouth - erythema, cracked lips, strawberry
tongue
Hands & feet - edema and/or erythema
Skin - polymorphous exanthem (ie- any rash)
Unilateral, cervical lymphadenopathy
37. Rheumatic Fever
A post-infectious connective tissue disease
Follows GAS pharyngitis by 3 weeks (vs. nephritogenic
strains of GAS)
Injury by GAS antibodies cross-reacting with tissue
Dx – JONES criteria (major and minor)
Tests – Throat Cx, ASO titer, CRP, ESR, EKG, +/-
ECHO
Rx – PCN x10 days and high-dose ASA or steroids
2o Prophylaxis – daily po PCN or monthly IM PCN
38. Rheumatic Fever – organs
affected
1. Heart muscle & valves – myocarditis &
endocarditis (pericarditis rare w/o the others)
2. Joints – polyarthritis
3. Brain – Sydenham’s Chorea (“milkmaid’s grip” or
better yet, “motor impersistance”)
4. Skin – erythema marginatum (serpiginous border)
due to vasculitis
5. Subcutaneous nodules – non-tender, mobile and on
extensor surfaces
