cyanotic heart defects Flashcards
when may recognition of cyanotic heart defects be delayed
when there is delay in DA closure
R→L shunt
what does central cyanosis indicate
almost always due to cyanotic heart defect
signifies R
what is transposition of the great arteries
aorta comes out of RV
PA comes out of LV
no shunt between these 2 circulations
baby will not be able to survive very long as no oxygenation takes place
what happens to the blood in transposition of the great arteries
systemic blood in SVC and IVC → RA → RV → aorta → systemic circulation
pulmonary veins → LA → LA → pulmonary artery → lungs
what would be necessary alongside coarctation of the aorta in order to survive
PDA, ASD/VSD
management of transposition of the great arteries
- recognised antenatally
- prostaglandin administered when baby is delivered - keeps DA open
- umbilical venous catheter placed
- if duct does close - Rashkind procedure
what is a Rashkind procedure
- advancing a catheter from a femoral vein into the RA
- fossa ovalis is still patent for a short time after delivery
- catheter pushed across to the LA
- ballon inflatedand put back through the foramen ovale - removes atrial septum so blood mixing can occur
definitive procedure for transposition
switch procedure
what is a switch procedure
- happens under full cardiopulmonary bypass
- aorta and PA clamped off and removed
- patch cut out around the coronary arteries and will be plugged into the stump of the large vessels on the L side
- aortic stump on the R will be refashioned after the patches have been taken out and the pulmonary trunk will be attached
- new aorta is connected to the left side
what happens if the coronary arteries are damaged during a switch procedure
if they are damaged, on reperfusion the baby will have an MI
what 4 abnormalities are seen in tetralogy of fallot
- ventricular septal defect (VSD)
- pulmonary stenosis
- misplaced aorta - overriding aorta
- thickened right ventricular wall (right ventricular hypertrophy)
pressure and shunting in tetralogy of Fallot
RV pressure is so high it surpasses LV pressure
R → L shunt over the VSD
baby becomes cyanosed
correction of tetralogy of fallot
most babies do well and won’t require major intervention until full correction of the tetralogy takes place ~6m/o
palliative measures for tetralogy of fallot
beta blockers
Blalock Taussig shunt - if the baby is very cyanosed
when do cyanotic spells occur in tetralogy of fallot
usually due to an increased use of oxygen
increased movement
stress of the baby
- baby becomes blue
- sats drop from normal >70% in tetralogy to 40s
