A five day old, full term male infant was severely cyanotic at birth. Prostaglandin E was administered initially and later ballooned atrial septostomy was done which showed improvement in oxygenation. The most likely diagnosis of this infant is –
Transposition of Great vessels is a condition characterized by aorta arising from the right ventricle and pulmonary artery from the left ventricle.
This results in complete separation of systemic and pulmonary circulation. Since systemic and pulmonary circulations are separate, survival depends on mixing of oxygenated pulmonary blood and deoxygenated systemic blood which can occur:
At Atrial level              :                    Through ASD
At Ventricle level          :                  Through VSD
At Great vessel level     :                 Through Patent ductus arteriosus
Oxygenation is normal in foetus but after birth as ductus arteriosus closes severe hypoxia occurs and in the
absence of VS.D, or ASD child presents with cyanosis and tachypnea at birth.
Tetralogy Fallot
Transposition of great vessels
Truncus Arteriosus
Tricuspid Atresia