Congenital Heart Disease
Embryologic Development
Cyanotic heart disease: (i.e. R to L shunt)
think: TGA/ Fallot
Acyanotic heart disease: (i.e. L toR shunt, obstruction occurring beyond lungs)
- Most critical period of fetal heart development is between 3-8 wks gestation
- Single heart tube grows rapidly forcing it to bend back upon itself and begin to assume the shape of a four chambered heart
- Insults at this time are most likely to lead to CHD
Cyanotic heart disease: (i.e. R to L shunt)
- blood bypasses the lungs --> no oxygenation occurs → high levels of deoxygenated haemoglobin enters the systemic circulation -->cyanosis
think: TGA/ Fallot
Acyanotic heart disease: (i.e. L toR shunt, obstruction occurring beyond lungs)
- blood passes through pulmonic circulation --> oxygenation takes place --> low levels of deoxygenated blood in systemic circulation --> no cyanosis