PEDIATRICS CONFERENCE
PATHOLOGY
OF
CONGENITAL HEART DISEASE
Boonyathee Sorawit MD.
Mar 25th , 2014
Epidemiology
Congenital heart disease occurs in 0.5–0.8% of live births.
Incidence is higher in stillborns (3–4%), spontaneous abortuses
(10–25%) and premature infants (about 2% excluding patent
ductus arteriosus [PDA])
About 2–3 in 1,000 newborn infants will be symptomatic with
heart disease in the 1st year of life.
The diagnosis is established by 1 week of age in 40–50% of
patients with congenital heart disease and by 1 month of age in
50–60% of patients.
Etiology
Caused by developmental abnormalities
Genetic factors
chromosomal abnormalities
outflow tract defect may cause by abnormal development of neural crest-
derived cell (region of chromosome 22)
Environmental factors, such as congenital infection or teratogens
Multifactorial: genetic, environmental, and maternal factors
The risk of recurrence of congenital heart disease increases if a
1st-degree relative (parent or sibling) is affected.
Chromosome Abnormalities
Down Syndrome (40%) AVSD, VSD
Trisomy 13 (80%) VSD, PDA
Trisomy 18 (100%) VSD, PDA
Turner’s Syndrome (35%) Coarctation of aorta
Marfan’s Syndrome Aortic aneurysm, MVP
Teratogen
Infection
Rubella PDA, peripheral PS
Drug
Dilantin PS, AS
Lithium Ebstein anomaly
Alcohol VSD, ASD
Retinoic acid Interrupted aortic arch, TGA, TOF
Maternal disease
Diabetes TGA, VSD, cardiomyopathy
SLE Complete AV block
Frequencies of CHD
VSD
ASD
Pulmonary stenosis
PDA
TOF
AVSD
42 %
10 %
8 %
7 %
5 %
5 %
How to Approach Congenital Heart Disease
History Taking
History of cardiology related
Heart Failure
Usually present in first year old
Tachypnea, Prolong feeding, Poor weight gain, Diaphoresis, pale
(sympathetic activity increased), Exercise intolerance
Cyanosis
Hypoxic Spell
Cyanosis, Tachypnea, Flaccid or loss of consciousness
Arrhythmia
Most common -> Supraventricular tachycardia
Neurologic Symptoms
Cerebral thrombosis, Brain Abscess
History Taking
Maternal and Perinatal History
History of drug used (Teratogen)
Birth weight
Family History
Usually prevalence 8 in 1,000
1st degree related increased in prevalence during 10 – 15 percent
Physical Examination
General Appearance
Finding dysmorphic feature
Vital Signs
Blood pressure -> Leg > Arm SBP 10-20 mmHg
Pulse
Weak Leg > Arm -> Coarctation of Aorta
Diminish pulse -> Cardiogenic shock or low cardiac output
Respiratory Rate (Upper limit)
< 1 month 60 /min
1 month – 1 year 50 /min
1 year – 5 years 40 /min
> 5 years 30 /mins
Physical Examination
Jugular Venous Pressure
Suspected right-side heart failure
Cardiac Exam
Inspection -> Precordial bulging (RV volume overload)
Palpation
Apex : 4th Lt intercostal space midclavicular line
Thrill for grading murmur
Auscultation
Physical Examination
Pulmonary Exam
Crepitation or Rales -> Pulmonary congestion
Complication : Pneumonia -> Left to Right Shunt
Liver and Spleen
Right-side heart failure -> Hepatomegaly or splenomegaly
Extremities
Edema -> Systemic venous congestion -> Right-side heart failure
Clubbing of finger -> Cyanotic heart
Chest X-Ray
Cardiovascular Structure
Location of Heart, Stomach and Liver
Levocardia, Mesocardia, Dextrocardia (Left, Central, Right)
Situs Solitus or Situs inversus
Chamber and Heart Enlargement
Cardiothoracic Ratio 50 – 60 %
Identified what chamber enlargement
Aorta
Right or Left Aortic Arch
Size of aorta
Chest X-ray
Pulmonary Vasculature
Increased pulmonary vasculature (Left to Right shunt)
Decreased pulmonary vasculature (Right to Left shunt, PS, PA)
Normal pulmonary vasculature (PS, AS)
Extracardiac Structure
Ribs and Vertebra
Diaphragm
Phrenic nerve paralysis, Diaphragmatic hernia
Lung parenchyma
Pneumonia or Atelectasis
Electrocardiography
Ventricular Hypertrophy (Right or Left)
Axis
Right Ventricular hypertrophy
• R wave >98th percentile in lead V1
• S wave >98th percentile in lead V6
• R wave in V1 + S wave in V6 >98th percentile
• R/S ratio >98 percentile in lead V1
• Right axis deviation
• qR pattern in V1
• Upright T wave in V1 (1 week old to 8 years old)
• RSR’ pattern in lead V1, where R’ >15 mm (<1
year old) or R’ >10 mm (>1 year old)
• Pure R wave in V1 >10 mm (newborn)
• RVH (by voltage criteria) with strain pattern
Left Ventricular Hypertrophy
• R wave >98th percentile in lead V6
• S wave >98th percentile in lead V1
• R wave in V6 + S wave in V1 >98th percentile
• Q wave >98th percentile in lead lll or V6
• R/S ratio >98th percentile in lead V6
• LVH (by voltage criteria) with strain pattern
Congenital heart disease
Cyanotic / Acyanotic
Three major categories:
left-to-right shunt
right-to-left shunt
obstruction
A shunt is an abnormal communication between chambers or
blood vessels
Direction and magnitude of shunt depends on
Size of defect
Relative pulmonary and systemic pressures
Relative pulmonary and systemic resistance
Congenital heart
disease
Cyanosis Acyanosis
Increase pulmonary
blood flow
Decrease pulmonary
blood flow
Normal pulmonary
blood flow
Increase pulmonary
blood flow
How to Approach Congenital Heart Disease
Acyanotic Congenital Heart Disease
Acyanotic Heart Disease
Left to Right Shunt
Increased pulmonary blood flow
Clinical -> Heart Failure
VSD, ASD, PDA, AVSD
Obstructive Lesions
Normal pulmonary blood flow
Clinical -> Exercise intolerance
PS, AS, Coarctation of aorta
Acyanosis
Increase pulmonary
blood flow
Normal pulmonary
blood flow
RVH LVHRVHLVH
ASD
PAPVR
PS
MSVSD
PDA
AVSD
AS
CoA
Increased pulmonary blood flow
Acyanotic Congenital Heart Disease
Atrial Septal Defect (ASD)
5 – 10 % of Total congenital heart diseases
2-fold of Female than male
Three types exist : primum, secundum and sinus venosus
The most common is the secundum type (Patent Foramen
Ovale; PFO)
Type of ASD
The Cardiovascular System
Cochard, Larry R., PhD, Netter's Atlas of Human Embryology, Updated Edition, Chapter 4, 83-111
Pathophysiology
Clinical Presentation
Usually incidental finding heart murmur without symptoms
1% of first year -> Developed heart failure
Clinical heart failure depended on shunt
Physical examination
Increased right ventricular impulse
Systolic ejection murmur at left upper sternal border (Relative PS)
Widely fixed split second heart sound -> prolong ejection time
Investigation for Diagnosis
Plain film (CXR)
can be normal is early stages +/- when the ASD is small
signs of increased pulmonary flow (shunt vascularity)
enlarged pulmonary vessels
upper zone vascular prominence
vessels visible to the periphery of the film
eventual signs of pulmonary arterial hypertension
chamber enlargement
right atrium
right ventricle
note : left atrium is normal in size & aortic arch is small to normal
Investigation for Diagnosis
Chest X-ray
Investigation for Diagnosis
Electrocardiography
Right axis deviation
Right atrial enlargement
Right ventricular hypertrophy (rsR’ in V1 80-90 %)
Complications
Right-side heart failure
Right side of the heart to work harder (Volume overload)
Arrhythmias
Atrial enlargement -> Atrial Fibrillation
Stroke
Clot pass Right to Left to Systemic circulation
Pulmonary Hypertension
Treatment
Ventricular Septal Defect (VSD)
Most common of congenital heart disease (20 – 30 %)
Type of VSD
Subpulmonic VSD
Perimembranous VSD
Inlet VSD
Muscular VSD
Pathophysiology
Clinical Presentation
Depended on VSD size and Pulmonary vascular resistant
Small VSD
Usually asymptomatic
Can detect murmur in 1st or 2nd weeks after birth
Pansystolic murmur at Left lower parasternal border
Moderate to Large VSD
Developed heart failure in 1 – 2 months
Murmur same as small VSD and loud P2
Eisenmenger’s Complex
Eisenmenger’s Complex
Consequence of a large preexisting left-to-right shunt
Pulmonary artery pressures approach systemic levels and the
direction of the flow becomes bidirectional or right to left.
The high pulmonary vascular resistance is usually established
in infancy (by age 2 years, except in ASD) and is sometimes
present from birth.
Eisenmenger’s Complex
Left to Right Shut
Increased pulmonary blood flow
(Shear stress / Circumferential stretch)
Endothelial dysfunction and vascular remodeling
(Smooth muscle cell proliferation, Increased in extracellular matrix, Intravascular thrombosis)
Increase in PVR
Inverted shunt : Right to Left
Cyanosis (Irreversible Process)
Investigation for Diagnosis
Plain Film
The chest radiograph can be normal with a small VSD.
Larger VSDs may show cardiomegaly
Left atrial enlargement
Right and left ventricle can be enlarged
A large VSD may also show features of pulmonary oedema, pleural
effusion or / and increased pulmonary vascular markings.
Investigation for Diagnosis
Chest X-ray
Investigation for Diagnosis
Electrocardiography
Small VSD : Normal EKG
Moderate VSD : LVH (R in Lead V6 high and can be found deep Q)
Large VSD : RVH and LVH
Treatment
Spontaneous Closure (35 –
40 % within 2 years)
Below 6 months that can’t
control heart failure or
recurrence pneumonia
6 – 24 months should
surgery in pulmonary
hypertension case
Atrioventricular Septal Defect (AVSD)
Endocardial cushion defect
4 – 5 % of Total congenital heart disease
40 % of Down Syndrome -> CHD
40 % of CHD in Down Syndrome -> AVSD
Type of AVSD
Complete AVSD
Primum ASD + Inlet VSD + Common AV valve
Partial AVSD
Primum ASD +/- Cleft of Mitral valve
Transitional (Intermediate) AVSD
Primum ASD + Small VSD but Separate Mitral and Tricuspid valve
Pathophysiology
Clinical Presentation
Partial and Intermediate AVSD
Can be developed heart failure in infant
Cardiac murmur
Systolic ejection murmur (Relative PS)
Widely fixed split S2
Pansystolic murmur at Apex (MS)
Complete AVSD
Within 4-8 weeks after birth can be developed heart failure
Cardiac murmur same as above and Loud P2
Investigation for Diagnosis
Plain Film
Not specific can be found chamber enlargement
Increased Pulmonary Vasculature
Investigation for Diagnosis
Chest X-ray
Investigation for Diagnosis
Electrocardiography
Left superior QRS axis (Lead I : positive and aVF : negative)
Right ventricular hypertrophy or combine ventricular hypertrophy
Treatment
Patent ductus arteriosus (PDA)
9 – 12 % of Total
congenital heart
disease
2 fold of prevalence in
female than male
80 % of Low birth
weight (1,200 gm)
Ductus arteriosus
Lung expansion
PVR↓ , PBF↑, PO2↑ PGE2↓ Ductus arteriosus constriction
Functionally closed; immediately after birth (within 10-15hr)
Anatomical closure; a week to 10 days
→ Ligamentum arteriosum
Pathophysiology
Clinical Presentation
Small duct with no LV volume overload (normal LV) and normal
PAP (generally asymptomatic)
Moderate PDA with predominant LV volume overload:
large LV with normal or reduced function (may present with left
heart failure)
Moderate PDA with predominant PAH:
pressure-overloaded RV (may present with right heart failure)
Large PDA:
Eisenmenger physiology with differential hypoxaemia and
differential cyanosis (lower extremities cyanotic, sometimes left
arm, too)
Investigation for Diagnosis
Plain Film
may vary depending on
isolated or associated with other cardiac anomalies
direction of shunt flow (right to left or left to right).
Can have cardiomegaly
predominantly left atrial and left ventricular enlargement
Investigation for Diagnosis
Chest X-ray
Investigation for Diagnosis
Electrocardiography
Small PDA : normal
Medium to Large PDA :
LA enlargement (wide P wave > 2.5 mm)
LV hypertrophy (R wave in lead V6 > 98th percentile)
+/- ST elevation (decreased diastolic filling time -> myocardial ischemia)
Treatment
Preterm with congestive heart failure
Restrict fluid with corrected anemia (Keep Hct > 45%)
Indomethacin should be used within 10 days
Low birth weight : 0.2 mg/kg in first dose and 2nd – 3rd dose q 12-24 hrs
< 2 days : 0.1 mg/kg
2-7 days : 0.2 mg/kg
> 7 days : 0.25 mg/kg
Small PDA
should perform intervention if more than 1 year old
Medium to Large PDA with clinical heart failure
should perform intervention as soon as possible
Treatment
Normal pulmonary blood flow
Acyanotic Congenital Heart Disease
Coarctation of aorta (CoA)
6 – 8 % of Total congenital
heart disease
2-fold of prevalence in male
than female
35 % associated with Turner
syndrome
Type of Coarctation of aorta
Simple CoA -> +/- PDA
Complex CoA -> Associated
with other congenital heart
disease
Pathophysiology
Clinical Presentation
Depended on severity of stenosis and other congenital heart
disease
critical CoA
Shock, Hypotension, Congestive heart failure
Ductal Dependent systemic blood flow
Anemia, Poor perfusion, Tachypnea
Weak pulse and BP Leg > Arm
Differential cyanosis Leg < Arm (Except Large PDA)
Adulthood may be present hypertension unknown caused
Systolic ejection murmur at left upper sternal border
Investigation for Diagnosis
Plain Film
rib notching
Compression of intercostal collateral arteries below rib
3 sign
Proximal to stenosis -> enlargement
Distal to stenosis -> narrow
pulmonary vascular marking normal
Chest X-ray
Investigation for Diagnosis
Electrocardiography
critical CoA
Right ventricular hypertrophy
Pumping of right ventricle -> ductus arteriosus -> descending aorta
Treatment
Critical CoA
Maintain Airway
Prostaglandin E 1 for opening ductus arteriosus
Coarctation repair
Treatment
Pulmonary Stenosis (PS)
25 – 30 % of total congenital heart disease
Type of pulmonary stenosis
Pulmonary valve stenosis
Infundibular stenosis
Pulmonary artery stenosis
Clinical Presentation
Subinfundibular/infundibular:
asymptomatic or they may present with angina, dyspnoea, dizziness, or
syncope
Valvular:
Mild to moderate valvular PS (Usually asymptomatic)
Moderate PS can progress at the valvular level (calcification) or at the subvalvular
level, due to reactive myocardial hypertrophy
Severe stenosis
dyspnoea and reduced exercise capacity, and have a worse prognosis
Supravalvular:
asymptomatic or have symptom of dyspnoea and reduced exercise
capacity
Investigation for Diagnosis
Plain film
Non specific
normal heart size
Right ventricular hypertrophy
Dilated pulmonary trunk or a main pulmonary artery
Electrocardiography
Right axis deviation
Right atrial enlargement
Right ventricle hypertrophy
Chest X-ray
Treatment
Mild PS
Follow up and aware bacterial endocarditis prophylaxis
Moderate to Severe PS
Balloon pulmonary valvuloplasty
Valvulotomy in case fail balloon valvuloplasty or dysplastic
pulmonic valve
Critical PS
Need ductus arteriosus should give prostaglandin E1 and corrected
anemia
Treatment
Aortic Stenosis (AS)
3-8 % of total congenital heart disease
4-fold of prevalence in male than female
Type of aortic stenosis
Aortic valve stenosis
Subaortic stenosis
Supravalvular aortic stenosis
Clinical Presentation
90 % Asymptomatic
10 % developed heart failure in first year
2/3 occur in 1-2 months
Tachypnea, low birth weight, hepatomegaly
Critical AS
Cardiogenic shcok, poor perfusion
Ductal dependent systemic blood flow
+/- Difference cyanosis (Due to PA pass to Aorta)
Investigation for Diagnosis
Plain Film
Usually normal cardiac size
Critical AS -> Cardiomegaly
Electrocardiography
Critical AS
Right atrial enlargement
Right ventricle hypertrophy
In adulthood
Left ventricular hypertrophy
+/- inverted T wave or ST depression in lead V5 and V6 due to myocardial
ischemia in severe stenosis
Treatment
Mild AS
No specific treatment -> F/U clinical and echocardiogram q 1-2 year
Moderate AS (PPSG 50–75 mmHg) or EKG change or have
symptom
Balloon valvuloplasty or valvulotomy
Severe AS (PPSG > 75 mmHg)
Suggest Balloon valvuloplasty or valvulotomy even though no
clinical symptom
Critical AS
Prostaglandin E1
Inotropic drug
Treatment
Cyanotic Congenital Heart Disease
Acyanotic Heart Disease
Decreased pulmonary blood flow
Right ventricular outflow tract obstruction ->
right–to–left shunt
Increased pulmonary blood flow
Can be developed to congestive heart failure and cyanosis
Cyanosis
Decrease pulmonary
blood flow
Increase pulmonary
blood flow
RVH CVHRVHLVH
TOF
PA/VSD
Critical PS
DORV/PS
TGA/VSD/PS
TGA
TAPVR
DORV
HLHS
PA/IVS
Tricuspid
atresia
Truncus
arteriosus
Decreased pulmonary blood flow
Cyanotic Congenital Heart Disease
Tetralogy of Follot (TOF)
Most common in cyanotic congenital heart disease
9 % of total congenital heart disease
4 Common of defect
Ventricular septal defect
Pulmonary stenosis
Overriding of aorta
Right ventricular hypertrophy
Pathophysiology
Clinical Presentation
Early clinical presentation
A heart murmur in infancy and progressive cyanosis (from right to
left shunting at the ventricular level secondary to RVOTO).
Unoperated tetralogy carries a poor prognosis (.95% of patients
used to die before 40 years of age).
Late clinical presentation
Late survival after tetralogy repair is excellent, with a 35-year
survival of 85%.
Hypoxic Spell
Increased
Right to Left shunt
Hypoxia
Metabolic Acidosis
Hyperpnoea
Increased
systemic venous return
InfundibularSpasm
Decreased Systemic vascular resistance
Investigation for Diagnosis
Plain Film
Boot shape heart
Apex shift with pulmonary trunk indentation
Decreased pulmonary marking
Electrocardiography
Usually found Right ventricular hypertrophy
Chest X-Ray
Treatment
Hypoxic Spells (Emergency condition)
Knee-Chest Position
Control Crying
Oxygen supplement
Morphine 0.1 mg/kg (Sedate and reduce infundibular spasm)
IV Hydration and correct metabolic acidosis
+/- drug for increased systemic vascular resistance
Propranolol 1-4 mg/kg/day q 6-8 hrs
Correct Anemia
Surgery consideration
Treatment
Tricuspid Atresia (TA)
3 % of total congenital heart disease
Hemodynamic
Blood can’t flow from right atrium to right ventricle
Right Atrium -> Left atrium (Via ASD) -> Left ventricle)
Clinical presentation
Developed cyanosis in 1 month
Large VSD and no pulmonary stenosis
Heart failure due to decreased pulmonary vascular resistance
Progressive cyanosis due to restrictive VSD
Progressive pulmonary stenosis -> Hypoxic Spell
Cardiac murmur
Pansystolic murmur at left lower sternal border (restrictive VSD)
Systolic ejection murmur (pulmonary stenosis)
Single second heart sound
Investigation for Diagnosis
Plain Film
Normal or minimal cardiomegaly
Decreased pulmonary vascular marking
Electrocardiography
Left superior QRS axis
R wave amplitude in lead V1 low (due to hypoplastic right ventricle)
+/- Left ventricular hypertrophy
Treatment
Newborn with severe cyanosis
Give PGE1 dose 0.05–0.1 mcg/kg/min for maintain ductus arteriosus
Consider modified Blalock-Taussig shunt
If restrictive ASD -> balloon atrial septostomy
Large VSD and no pulmonary stenosis
For prevent to develop heart failure -> pulmonary artery banding
Timing for Operation
6 – 12 months
Bidirectional Glenn shunt
Superior vena cava -> pulmonary artery
3 – 4 year
Fontan operation or total cavopulmonary shunt
Inferior vena cava -> pulmonary artery
Treatment
Increased pulmonary blood flow
Cyanotic Congenital Heart Disease
Transposition of Great Arteries (TGA)
5 % of total congenital heart disease
Ventriculo-arterial discordance:
Left ventricle to pulmonary artery
Right ventricle to aorta
Pathophysiology
Clinical Presentation
Pure TGA with small PFO and PDA
Cyanosis after birth, metabolic acidosis
Weak murmur, single second heart sound
TGA with VSD
Minimal cyanosis
Developed heart failure in 2-6 months
TGA with VSD with PS
Similar tetralogy of Fallot
Cyanosis but no clinical heart failure
Investigation for Diagnosis
Plain film
Cardiomegaly with a cardiac contours classically described as
appearing like an egg on a string.
Narrowing of the superior mediastinum as result of the aortic and
pulmonary arterial configuration.
Electrocardiography
Right axis deviation
Right ventricular hypertrophy
TGA with VSD -> combined ventricular hypertrophy
Chest X-ray
Treatment
Severe Cyanosis
PGE1: dose 0.05– 0.1 mcg/kg/min for maintain ductus arteriosus
Correct metabolic acidosis and electrolytes
If persistent cyanosis
Atrial balloon septostomy then consider arterial switch operation that
should perform within 2 weeks
If more than 2 weeks -> Two-stage arterial switch operation
Pulmonary banding -> For Left ventricle hypertrophy
Arterial switch after 7-10 days of pulmonary banding
Treatment
TGA with VSD and PS -> Palliative operation
modified Blalock–Taussig shunt then considered definite surgery
if body weight 10-15 kgs for Ratelli Operation
Closed VSD and used conduit bridging between right ventricle and
pulmonary artery
Treatment
Truncus Arteriosus
< 1 % of total congenital heart disease
Common route between pulmonary artery and aorta
Type of Truncus arteriosus
Clinical Presentation
Minimal Cyanosis
Can be developed heart failure in 1 month
Cardiac murmur : pansystolic murmur at left lower sternal
bonder
Single second heart sound
Investigation for Diagnosis
Plain Film
Cardiomegaly
Increased pulmonary marking
Electrocardiography
Left atrial enlargement
Combined ventricular hypertrophy
Treatment
Control heart failure during waiting for operation
Consider for Total repair (Should perform before 6 months)
Closed VSD
Connected conduit between right ventricle to pulmonary artery
If can’t do total repair
Pulmonary artery banding for prevent pulmonary vascular
obstructive disease
Treatment
Total Anomalous Pulmonary Venous Return
(TAPVR)
1.5 % of total congenital heart disease
Usually pulmonary vein must drainage into Left atrium but
blood returning from the lungs drains back to the right side of
the heart.
Pathophysiology
Type of TAPVR
Clinical Presentation
56 % Symptom presented in first month
Minimal cyanosis
Sign of Heart failure
Systolic ejection murmur at left upper sternal border (Relative PS)
Investigation for Diagnosis
Plain film
The right heart is prominent
because of the increased flow volume
The supracardiac variant (type I) can classically depict a snowman
appearance on a frontal chest radiograph, also known as figure of 8
heart or cottage loaf heart .
Chest X-Ray
Investigation for Diagnosis
Electrocardiography
Right axis deviation
Right atrium enlargement
Right ventricular hypertrophy
Treatment
Should perform Total repair as soon as possible
Double-outlet right ventricular (DORV)
Two Great Arteries (Aorta and Pulmonary Artery) both originate
from the right ventricle
Blood from the left ventricle passes across a VSD into the RV to
reach the great arteries
Double-outlet right ventricular (DORV)
Hypoplastic left heart syndrome (HLHS)
Left side of the heart is very poorly formed
Cannot support the main circulation.
Left ventricle and aorta are abnormally small (hypoplastic)
Treatment
Thank you for your kind attention.
Reference
Moss and Adams’ heart disease in infants, children, and
adolescents, 6 th ed. In: Allen HD, Gutgesell HP, Clark EB,
Driscoll DJ, eds. Philadelphia: Lippincott Williams & Wilkins,
2001:618-35.
The science and practice of pediatric cardiology, 2nd ed. In:
Garson A Jr, Bricker JT, Fisher DJ, Neish SR, eds. Baltimore:
Williams & Wilkins, 1998:1141–79.
Driscoll DJ. Left-to-right shunt lesions. Pediatr Clin North Am
1999;46:355–68.
Comprehensive surgical management of congenital heart
disease. In: Jonas RA, ed. London: Arnold, 2004:386-401.
Reference
Waldman JD, Wernly JA. Cyanotic congenital heart disease with
decreased pulmonary blood flow in children. Pediatr Clin North
Am 1999;46:385-404.
Victorica BE. Cyanotic newborns. In: Gessner IH, Victorica BE,
eds. Pediatric cardiology: a problem oriented approach.
Philadelphia, W.B. Saunders 1993:97-109.
Pediatric cardiac surgery. In: Mavroudis C, Backer CL, eds.
Philadelphia, Mosby 2003:383-97.
Picture Reference
http://radiopaedia.org
http://www.rch.org.au/cardiology/heart_defects/