2012. 11. 21

관동의대 제일병원

병리과 전이경

심장의 발생

심장의 발생

• embryo에서 최초로 기능을 하는 장기

• 수정 4 주 초 박동 시작

• 발생: 수정 후 3주- 8주

• 선천성 심장병: 가장 흔한 선천성 기형

Critical periods of development for various organ systems and the resultant malformations

Congenital Heart Disease

Frequency of Congenital Cardiac Malformations

Malformation Incidence/Million Live Births %

Ventricular septal defect (VSD) 4482 42

Atrial septal defect (ASD) 1043 10

Pulmonary stenosis (PS) 836 8

Patent ductus arteriosus (PDA) 781 7

Tetralogy of Fallot (TOF) 577 5

Coarctation of aorta (CoA) 492 5

Atrioventricular septal defect (AVSD) 396 4

Aortic stenosis (AS) 388 4

Transposition of great arteries (TGA) 388 4

Truncus arteriosus 136 1

Total anomalous pulmonary venous connection (TAPVC) 120 1

Total 9757

J Am Coll Cardiol 39:1890,2002

First week of development: Ovulation to implantation

Second week of development: Bilaminar germ disc

day12 day13

Third week of development: Gastrulation (trilaminar germ disc)

day16

20 days

Neurulation includes

the formation of the neural plate (day 18-19), neural folds (day 20-21), and the neural tube (day 22-26); the latter will develop into the future brain and spinal cord

Final closure

Anterior neuropore: 25th day

Posterior neuropore: 27th day

day 18

A, day 18

B, day 20

C, day 21

D, day 22*

Heart tube

Early Cardiac Morphogenesis I (Fertilization 3rd week)

• Cardiogenic crest in splanchnic mesoderm in front of the neural plate

• Bilateral endocardial tube from angioblastic cords

• Cephalic and lateral folding of the embryo

• Primary heart tube in the middle thorax

Early Cardiac Morphogenesis II (Fertilization 4th week)

• Segmentation : Sinus Venosus- Atrium

- AV canal- Ventricle - Bulbus Cordis

• Layering – Endocardium

– Myocardium

– Epicardium

– Cardiac jelly

• Looping

Atrium

Bulbus cordis

Ventricle

Sinus

venosus

AV

canal

day 22 day 23 day 24

Formation of Cardiac loop

Normal D-looping

Cardiac Segmentation, Layering, Looping

30 days

• Dextrocardia – Isolated form – Situs inversus

• Heterotaxy (Laterality sequences) – Polysplenia syndrome-

left isomerism – Asplenia syndrome-

right isomerism

Abnormalities of Cardiac Looping

Development of sinus venosus

ACV: anterior cardinal v. PCV: posterior cardinal v. UV: umbilical v. VIT: vitelline v. CCV: common cardinal v.

Fetal stage

Formation of cardiac septa

Atrial Septation (4-6 weeks)

Septum primum

ostium primum

Interventricular

foramen

ostium

secundum

Septum

secundum

35 days

• Primary septum (septum primum)

• Secondary septum (septum secundum)

• Intermediate septum (septum intermedium)- endocardial cushion

• Primary foramen (osteum primum)

• Secondary foramen (osteum secundum)

• Oval foramen (foramen ovale)

Atrial Septum

Secundum ASD (90%)

Endocardial cushion • Atrioventricular canal and conotruncal region

• Atrial and ventricular (membranous portion) septa

• Atrioventricular canals and valves

• Aortic and pulmonary channels

• Abnormalities in ECC formation • ASD, VSD, AVSD

• Defects involving great vessels (ex. persistent truncus arteriosus, TOF and TGA)

Neural crest cells in conotruncal region

35 days

Development of conotruncal ridges and closure of the interventricular foramen

6 weeks Beginning of 7 weeks

End of 7 weeks

7 weeks

Ventricular Septation (4주 말-8주) • Muscular interventricular septum + Membranous

part of interventricular septum

• Closure of interventricular foramen – Interventricular septum

– Atrioventricular ECC

– Outflow tract endocardial ridge

Formation of Ventriculoarterial Valve

5 weeks

6 weeks

7 weeks

6 weeks

7 weeks 9 weeks

Ventricular Septal Defect

• Most common congenital cardiac malformation

• Isolated or a/w abnormalities in partitioning of the conotruncal region

• Type – perimembranous (80-90%) – muscular (5-20%) – outlet or infundibular,

(doubly committed) juxta-arterial (5-7%)

Perimembranous type

Muscular type

(Doubly committed) juxta-arterial type Infundibular type Outlet type

Tetralogy of Fallot • Most common cyanotic CHD

• Conotruncal region 이상

• Unequal division of the conus resulting from anterior displacement of the conotruncal septum

• Four features

1) Ventricular septal defect

2) Subpulmonary stenosis

3) Overriding of aorta

4) Right ventricular hypertrophy

Persistent truncus arteriosus

• Conotruncal ridge – fail to fuse and to

descend toward the ventricles

– interventricular septum형성에도 관여하므로 언제나 interventricular septal defect동반

PT AO

LV

RV

Conotruncal septum

→ fail to follow its normal spiral course and run straight down

→ Aorta from RV, PA from LV

VSD, perimembranous type 동반하기도.

Transposition of Great Arteries

경청해주셔서 감사합니다☺