Describe the Complete transposition of great arteries ?

Lethal, relatively frequent malformation. Without treatment, it results in 30 per cent mortality within the first week of life, 50 per cent within the first month, 70 per cent within six month and 90 per cent mortality within the first year of life

Incidence: Complete transposition of the great arteries is the most common cyanotic congenital cardiac lesion - 5 per cent -7 per cent of all congenital cardiac malformations. Total incidence is reported to be between 0.2/1000 to 0.33/1000 live births. It occurs with a strong male predilection (60 per cent -70 per cent). Association with genetic syndromes is rare; incidence of familial occurrence is low.
Anatomy and Embryology Transposition of great arteries results from abnormal septation of the Aortopulmonary trunk during embryogenesis so that the Pulmonary trunk arises from the left and Aorta arises from the right ventricle. Aortic valve is placed more anteriorly, superiorly and to the right, relative to the pulmonary valve. The spatial relationship of the great vessels may be variable.

Figure: Complete transposition of the great arteries