The timing of surgery for tetralogy of Fallot is generally considered appropriate between the age of 4 months and 1 year, but it also depends on whether the child has frequent hypoxic episodes, if they are frequent, they must be done early, if they are rare, they can be done when they are a little older, the child’s ability to tolerate surgery increases, which can improve the success rate of surgery. Hypoxic episodes are characterized by marked difficulty in breathing, increased bruising, partial loss of consciousness, no longer responding to general stimuli such as eating and drinking, calling, no longer crying or just moaning, and can be fatal in severe cases, which is the most common cause of death in these children.