Congenital heart disease is an abnormality present at birth that affects the structure or function of the heart. The most common types are acyanotic conditions like atrial septal defects, ventricular septal defects, and patent ductus arteriosus which allow blood to flow from the left to the right side of the heart. Cyanotic conditions like tetralogy of Fallot and transposition of the great arteries prevent oxygenated blood from reaching the body. Abnormal development during embryogenesis can disrupt the normal partitioning of the heart, leading to these defects.

1. CONGENITAL
HEART DISEASE
Presenter : Dr Abdulrafey Usmani
Mmed. Paediatrics

2. INTRODUCTION
 Congenital cardiovascular disease is defined as
an abnormality in cardio-circulatory structure or
function that is present at birth, even if it is
discovered much later.
 Congenital cardiovascular malformations usually
result from altered embryonic development of a
normal structure or failure of such a structure to
progress beyond an early stage of embryonic or
fetal development.

3. EPIDEMIOLOGY
 About 0.8% of live births are complicated by a
cardiovascular malformation.
 PDA, Ebstein anomaly of the tricuspid valve,
and atrial septal defect (ASD) are more common
in females, whereas aortic valve stenosis,
coarctation of the aorta, hypoplastic left heart,
pulmonary and tricuspid atresia, and
transposition of the great arteries (TGA) are
more common in males.
 Extracardiac anomalies occur in about 25% of
infants with significant cardiac disease, and their
presence may significantly ↑mortality.

4.  General concepts regarding the etiology of
congenital malformations
o Unknown in almost 90% of cases
o Environmental factors:
Maternal rubella, ingestion of thalidomide and
isotretinoin early during gestation, and chronic
maternal alcohol abuse
o Genetic factors are also clearly involved
o well-defined associations with certain
chromosomal abnormalities (e.g., trisomies 13,
15, 18, and 21 and Turner syndrome)
ETIOLOGY

5. CLASSIFICATION OF CONGENITAL HEART
DISEASES
 Cyanotic or non-cyanotic
 Non-cyanotic: ASD, VSD, sinus venosus defect, patent
ductus arteriosus, aortic stenosis, pulmonary stenosis,
aortic coarctation
 Cyanotic: Tetralogy of Fallot, Ebstein’s anomaly,
transposition of the great arteries, Eisenmenger’s
syndrome, truncus arteriosus, tricuspid atresia, total
anomalous pulmonary venous return “5 Ts and 2 Es”

6. CLASSIFICATION OF CONGENITAL HEART DISEASES
 Simple or complex
Simple includes ASD, VSD, or singular
valvular abnormalities (Ebstein’s anomaly)
Complex includes those with multiple
defects, AV canal defects, or “single”
ventricle physiology

7. CLASSIFICATION OF CHD

8. NORMAL EMBRYOLOGIC DEVELOPMENT OF THE
HEART
 During the first month of gestation, the
primitive, straight cardiac tube is formed,
comprising the :
Sinuatrium (Most Cephalad),
 Primitive Ventricle,
 Bulbus Cordis, And
Truncus Arteriosus (Most Caudad) In
Series.

10. NORMAL EMBRYOLOGIC DEVELOPMENT OF THE
HEART
 In the second month of gestation, this tube
doubles over on itself to form two parallel
pumping systems, each with two chambers and
a great artery.
 The two atria develop from the sinuatrium.
 The AV canal is divided by the endocardial
cushions into tricuspid and mitral orifices, and
 The right and left ventricles develop from the
primitive ventricle and bulbus cordis.

12. NORMAL EMBRYOLOGIC DEVELOPMENT OF
HEART
 Differential growth of myocardial cells causes the
straight cardiac tube to bear to the right, and the
bulboventricular portion of the tube doubles over on
itself, bringing the ventricles side by side.
 Migration of the AV canal to the right and of the
ventricular septum to the left serves to align each
ventricle with its appropriate AV valve.
 At the distal end of the cardiac tube, the bulbus cordis
divides into a subaortic and a subpulmonary muscular
conus;
 The subpulmonary conus elongates and the subaortic
conus resorbs,allowing the aorta to move posteriorly and
connect with the left ventricle.

13. NORMAL DEVELOPMENT OF HEART

14. ABNORMAL DEVELOPMENT
 A host of anomalies can result from defects in this
basic developmental pattern.
 Double-inlet left ventricle is observed if the tricuspid
orifice does not align over the right ventricle.

15. ABNORMAL DEVELOPMENT
 The various types of persistent truncus
arteriosus result from failure of the truncus to
divide into main pulmonary artery and aorta.
 Double-outlet anomalies of the right ventricle
are produced by failure of either the
subpulmonary or subaortic conus to resorb
whereas resorption of the subpulmonary
instead of the subaortic conus may lead to
TGA.

17. ATRIA
 The primitive sinuatrium is separated into right and
left atria by the down growth from its roof of the
septum primum toward the AV canal, thereby
creating an inferior interatrial ostium primum
opening.
 Numerous perforations form in the anterosuperior
portion of the septum primum as the septum
secundum begins to develop to the right of the
septum primum, the coalescence of these
perforations forms the ostium secundum.
 The septum secundum completely separates the
atrial chambers except for a central opening—the
fossa ovalis—that is covered by tissue of the
septum primum, forming the valve of the foramen

19. ATRIA
 Fusion of the endocardial cushions anteriorly and
posteriorly divides the AV canal into tricuspid and
mitral inlets.
 The inferior portion of the atrial septum, the superior
portion of the ventricular septum, and portions of the
septal leaflets of both the tricuspid and mitral valves
are formed from the endocardial cushions.
 The integrity of the atrial septum depends on growth
of the septum primum and septum secundum and
proper fusion of the endocardial cushions.
 ASDs and various degrees of AV defect are the result
of developmental deficiencies of this process.

21. VENTRICLES
 Partitioning of the ventricles occurs as cephalic
growth of the main ventricular septum results in
its fusion with the endocardial cushions and the
infundibular or conus septum.
 Defects in the ventricular septum may occur
because of :
 a deficiency of septal substance;
 malalignment of septal components in different
planes preventing their fusion; or
 an overly long conus, keeping the septal
components apart.
 These defects probably generate the VSDs in
tetralogy of Fallot and transposition

22. GREAT ARTERIES
 The truncus arteriosus is connected to the dorsal
aorta in the embryo by six pairs of aortic arches.
 Partition of the truncus arteriosus into two great
arteries is a result of the fusion of tissue arising from
the back wall of the vessel and the truncus septum.
 Rotation of the truncus coils the aortopulmonary
septum and creates the normal spiral relation
between aorta and pulmonary artery.
 Semilunar valves and their related sinuses are
created by absorption and hollowing out of tissue at
the distal side of the truncus ridges.
 Aortopulmonary septal defect and persistent truncus
arteriosus represent various degrees of partitioning
failure

25. SPECIFIC CARDIAC
DEFECTS

26. ACYANOTIC
CHD

27. ACYANOTIC CHD
 Left-to-Right Shunts
 The three most important and common types
of acyanotic congenital heart disease are:
 • Atrial septal defect.
 • Ventricular septal defect.
 • Patent ductus arteriosus.

28. ATRIAL SEPTAL DEFECT (ASD)
 Four types of ASDs or interatrial
communications exist:
Ostium primum,
Ostium secundum,
 Sinus venosus, and
 Coronary sinus defects.

29. ASD

30. OSTIUM PRIMUM
•15% of all ASDs
•Occur if the septum primum and endocardial cushion fail to fuse
and are often associated with abnormalities in other structures
derived from the endocardial cushion (e.g., mitral and tricuspid
valves).
•Occurs in the lower part of the atrial septum, adjacent to the
atrioventricular valves, deformed and regurgitant
•Also associated with cleft in anterior mitral valve leaflet or septal
leaflet of the tricuspid valve.
• Common in Down syndrome

31. OSTIUM PRIMUM

32. OSTIUM SECUNDUM
•Defect in fossa ovalis,
midseptal
•Represents 75% of all
ASDs
•Occurs when the septum
secundum does not enlarge
sufficiently to cover the
ostium secundum
•Associated with mitral valve

33. SINUS VENOSUS DEFECT
•Located in the upper atrial
septum, near the entry of the
superior vena cava
•Represents 10% of all ASD
defects
•Associated with anomalous
pulmonary venous connection
from the right lung to the
superior vena cava or right

34. PATENT FORAMEN OVALE (PFO)
•The foramen ovale is a tunnel-like space between
the overlying septum secundum and septum primum
and typically closes in 75% of patients at birth by
fusion of the septum primum and secundum.
•In utero the foramen ovale is necessary for blood
flow across the fetal atrial septum.
•Oxygenated blood from the placenta returns to the
IVC, crosses the foramen ovale, and enters the
systemic circulation.
•In about 25% of pts, a PFO persists into adulthood.

36. VENTRICULAR SEPTAL DEFECT (VSD)
 VSD is an abnormal
opening in the
ventricular septum,
which allows free
communication
between the Rt & Lt
ventricles
 Accounts for 25% of
CHD

37. VENTRICULAR SEPTAL DEFECT
 The ventricular septum can be divided into three major
components—inlet, trabecular, and outlet—all abutting
on a small membranous septum lying just underneath the
aortic valve.
 VSDs are classified into three main categories according
to their location and margins .
 Muscular VSDs are bordered entirely by myocardium and can
be trabecular, inlet, or outlet in location.
 Membranous VSDs often have inlet, outlet, or trabecular
extension and are bordered in part by fibrous continuity
between the leaflets of an AV valve and an arterial valve.
 Doubly committed subarterial VSDs are more common in
Asian patients, are situated in the outlet septum, and are
bordered by fibrous continuity of the aortic and pulmonary
valves.

38. COMPONENTS OF VSD

39. VSD
 A restrictive VSD does not cause significant
hemodynamic derangement and may close
spontaneously during childhood and sometimes in adult
life.
 A moderately restrictive VSD imposes a
hemodynamic burden on the left ventricle, which leads
to left atrial and ventricular dilation and dysfunction as
well as a variable increase in pulmonary vascular
resistance.
 A large or nonrestrictive VSD features left ventricular
volume overload early in life with a progressive rise in
pulmonary artery pressure and a fall in left-to-right

42. PATENT DUCTUS ARTERIOSUS
 The ductus arteriosus derives from the left sixth primitive
aortic arch and connects the proximal left pulmonary artery
to the descending aorta, just distal to the left subclavian
artery.
 The ductus is widely patent in the normal fetus, carrying
deoxygenated blood from the right ventricle through the
descending aorta to the placenta, where the blood is
oxygenated.
 Functional closure of the ductus from vasoconstriction
occurs shortly after a term birth, whereas anatomical
closure from intimal proliferation and fibrosis takes several
weeks to complete.
 patency of a ductus is a true congenital malformation

43. PDA

45. CYANOTIC HEART
DISEASE

46. TETRALOGY OF FALLOT (TOF)
 The 4 components of TOF are
 An outlet VSD,
 Obstruction to right ventricular outflow,
 Overriding of the aorta (<50%), and
 Right ventricular hypertrophy.
 The fundamental abnormality contributing to each of these
features is anterior and cephalad deviation of the outlet
septum, which is malaligned with respect to the trabecular
septum.
 The dominant site of obstruction is usually at the sub-valve
level.
 Progressive hypoxemia in the first years of life is
expected. Survival to adult life is rare without

47. TOF

48. TRANSPOSITION OF THE GREAT ARTERIES
 This is a common and potentially lethal form of heart
disease in newborns and infants.
 The malformation consists of the origin of the aorta from
the morphological RV and that of the PA from the
morphological LV.
 Consequently, the pulmonary and systemic circulations
are connected in parallel rather than the normal in-series
connection.
 In one circuit, systemic venous blood passes to the right
atrium, the right ventricle, and then to the aorta.
 In the other, pulmonary venous blood passes through the left
atrium and ventricle to the pulmonary artery.
 This situation is incompatible with life unless mixing of the
2circuits occurs.

49. TRANSPOSITION OF THE GREAT ARTERIES
1=transposition of the
great arteries;
2=atrial baffles;
3=pulmonary vein
blood flow through
tricuspid valve to RV;
4=IVC and SVC blood
flow through mitral
valve to LV

50. EBSTEIN ANOMALY
 The common feature in all cases of Ebstein anomaly is apical
displacement of the septal tricuspid leaflet in conjunction with
leaflet dysplasia.
 Although the anterior leaflet is never displaced apically, it may be
adherent to the free wall of the right ventricle, causing right
ventricular outflow tract obstruction.
 The displacement of the tricuspid valve results in
“Atrialization” (functioning as an atrial chamber) of the inflow
tract of the right ventricle and consequently produces a
variably small, functional right ventricle.
 Associated anomalies include PFO or ASD in ≈ 50% of patients.

51. EBSTEIN ANOMALY