Congenital Heart Disease Flashcards
How do left-to-right shunts present? Name some examples:
BREATHLESS:
1) Ventricular septal defect
2) Persistant arterial duct
3) Atrial Septic defect
How do right-to-left shunts present? Name some examples:
BLUE/CYANOTIC:
1) Tetralogy of the fallout - cyanosis at 1-2months
2) Transposition of the great arteries - cyanosis in first days of life
How does common mixing present? Name one example:
BREATHLESS AND BLUE:
1) Atrioventricular septal defect (AVSD)
Outflow obstruction in a well child - name some examples and how does it present?
Asymptomatic murmur:
1) Aortic stenosis
2) Pulmonary stenosis
Outflow obstruction in a sick neonate - name an example and how does it present?
COLLAPSED WITH SHOCK
1) Coarctation of the aorta
Circulatory changes at birth:
- In the foetus, left atrial pressure low as little blood return from lungs.
- Pressure in right atrium is higher than in the left - it receives all the systemic venous return including blood from placenta (umbilical vein).
- Foramen of ovale is held open by blood flowing from RA to LA across atrial septum, and into the LV and then to the upper body.
- At birth, with the first breaths, resistance to pulmonary blood flow falls, alveolar O2 pressure rises and results in the vasodilation of pulmonary vessels.
- This increases blood flowing into lungs, and hence pressure in atria rises.
- The voluming of blood returning to the RA falls as the placenta is excluded from circulation.
- Pressure changes cause closure of foramen of ovale - now becomes fossa ovalis.
- Ductus arteriosus - connects pulmonary artery to the aorta in fatal life - will normally close in the first few hours/days.
What is duct dependant circulation?
Some babies with congenital heart lesions rely on blood flow from the ductus arteriosus - their clinical condition will deteriorate dramatically when the duct closes - explains why some lesions may not become apparent until a few weeks of age.
