2012. 11. 21 관동의대 제일병원 병리과 전이경 심장의 발생
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☺