Hyperoxia test
p02 >150mmHg after breathing Fi02 for 10 mins = unlikely cyanotic heart disease
Fail = right to left shunt somewhere
More conservative
<50 TGA
<100 other cyanotic
100-220 ?cardia ?resp
>220 resp
Fail = right to left shunt somewhere
More conservative
<50 TGA
<100 other cyanotic
100-220 ?cardia ?resp
>220 resp