Natural history of cyanotic malformations and comparison of all common cardiac malformations.

At birth, cyanotic malformations are about 20 per cent of all cardiac malformations. But only Fallot's tetralogy and transposition of the great arteries reach an incidence of the same order as ,several acyanotic malformations. In children at hospital clinics, only Fallot's tetralogy retains a similar position. The mortality of all cardiac malformations in the first year of life is very high, but for truncus arteriosus and transposition it is so high that at clinics for older children and adults few examples of the former