先天性心脏病课件.pptVIP

Congenital Heart Diseases (CHD)先天性心脏病 General conceptCHD occurs in approximately 6-8‰ live births In China, alone 250000 children with CHD are born each year30% of cases may die within first year of lifeThe etiology remains unsolvedSecondary prevention is the strategy at this stageCongenital Heart Diseases (CHD)先天性心脏病 Schematic Diagram of CardiogenesisBilaterally symmetrical cardiac progenitor cells form distinct regions of the heartThe precardiac mesodermal cells give rise to a linear heart tubeForming a rightward loopEstablishing the spatial orientation of the four-chambered mature heart Schematic Diagram of CardiogenesisLVRVLAPAAOconotruncusRV=right ventricle; LV=left ventricle; RA=right atriumAo=aortic; LA=left atrium; PA=pulmonary arteryRA Fetal developmentOne month5th week6th week8th week Cardiac development Formation of a single Heart tubeFormation of the heart loop Cardiac developmentOut flow tract septationSeptation of fourchambers 原发房隔原发孔继发房隔原发房隔继发孔继发房隔Atrial septation Molecular understanding of CHDCHD GeneGene CHD10％－15％ may caused by single gene85％ may caused by polygenic disorders Fetal and postnatal circulations胎儿血循环与出生后改变 Diagrammatic representation of fetal circulation Gas and nutritional requirements exchange occurs in the placentaPulmonary blood flow is very lowForamen ovale and ductus arteriosus are opened The blood saturation is higher in up limbs and head Fetal Circulation Pulmonary ventilation, and respiration, pulmonary vascular resistance decreases rapidly, systemic blood saturation increasedThe ductus arteriosus closed by its contraction of muscular wall, which resulted by bradykininBy increasing in pulmonary blood flow, pulmonary venous return increased, combined with a decrease in pressure within the right atrium, resulted in a closing of foramen ovalePostnatal Circulations Ductus arterious closure full term baby: 80% closed within 24 hours after birth , 95％anatomic closure within the first year