1

Dr Anil Dwivedi

2

Outline

Early development with regulating Genes.

Primordial Heart circulation.

Partitioning of AV canal.

Partitioning of Primordial Atrium.

Changes in Sinus Venosus.

3

Formation of RA & LA.

Partitioning of Primordial Ventricle & BC.

Development of Cardiac Valves & Conducting System.

Congenital Anomalies.

4

DEVELOPMENT OF HEART

•CVS – 1st major system.•why?•From-

•splanchnic mesoderm•paraxial & lat meso •neural crest cells.

•Earliest sign – angioblastic cords.

5

•18 days embryo.•Dorsal view

6

•Angioblastic cord in cardiogenic area.•Pericardial coelom.

7

•4th week•Effect of head fold on position of Heart•Septum transversum-central tendon of Diaph.

8

•20 days•Dorsal view•Two endocardial Heart tube & lat fold.

9

•22 days•Formation of pericardial cavity & fusing heart tubes•Single Heart tube suspended by dorsal mesocardium

10

•28 days•Degeneration of central part of dorsal mesocardium•Formation of Tr. Sinus•Three layers of Heart wall.

11

Genetic basis of growth of heart tube

6 HLH

12

•Rt & Lt Heart tubes•Cranial to caudal fusion•Partial fusion of Sinus Venosus.

13

Subdivisions of Heart tube & their fate

14

26 dayshorns of sinus Venosus

15

16

• The Bulbus cordis moves Inf Ant & to the embryo Rt.

• The primitive ventricle moves to Lf

• The prim Atrium & Sinus venosus moves sup & post

• Sinus venosus is post to atrium.

Early Heart development & folding of primitive Heart tube

17

Early Heart development & folding of primitive Heart tube

18

Circulation through primordial Heart

19

Partitioning of Atrioventricular canal

20

Partitioning of Atrioventricular canal

Partition of the Atrioventricular canal

22

Partitioning of primordial Atrium

•4th week•Septum primum•Foramen primum•Foramen secundum•Septum secundum•Foramen ovale

23

Partitioning of primordial Atrium

24

Partitioning of primordial Atrium

25

Partitioning of primordial Atrium

26

Partitioning of the primordial atrium

27

Changes in the Sinus Venosus

28

Changes in the Sinus Venosus

29

Changes in the Sinuatrial Orifice

30

Formation of the Right AtriumRt ½ primitive atriumSinus venosusRt ½ AV canal

31

Formation of the Right Atrium

32

Formation of the Left Atrium & PPV

33

Partitioning of primordial Ventricle

34

Partitioning of primordial Ventricle

35

Partitioning of primordial Ventricle

36

Partitioning of Bulbus Cordis & TA

37

Developments of the Cardiac Valves

38

Developments of the Cardiac Valves

39

Developments of the Cardiac Valves

40

Conducting system of the Heart

41

Anomalies of the Heart

42

Anomalies of the Heart

• Dextrocardia

Anomalies of Position

43

Anomalies of the HeartAnomalies of PositionEctopia Cardis

44

Atresia or Stenosis

• Aortic valve Stenosis• Pulmonary valve Stenosis

45

Defective formation of septa

ASD• Patent oval foramen.• F>M• Probe patent foramen

incomplete adh of sep sec.

46

Defective formation of septaASD• Ostium secundum ASD

47

Defective formation of septaASD• Endocardial cushion defect with Ostium primum ASD

48

Defective formation of septaASD

• Sinus Venosus ASD

• Common Atrium.

49

Defective formation of septaVSD- most common CHD. -25%, M>F, • Membranous – most common.

50

Defective formation of septaVSD• Muscular(Swiss cheese)• Single ventricle

51

Persistent Truncus ArteriosusFailure of-• Truncal ridges• aorticopulmonaryseptum

52

Transposition of Great Arteries

53

Tetralogy of Fallot• Pulmonary Stenosis• VSD• Overriding of aorta• Right ventricular

hypertrophy

Unequal div of TA

54

SUMMARY

1. Formation and division of the heart tube;

2. Partitioning of Atrioventricular canal, atrium, ventricle, and Truncus and Bulbus;

3. Congenital heart diseases.