clinical features

Last reviewed 02/2023

Progressive cyanosis develops during the first few days of life as the ductus arteriosus and foramen ovale begin to close.

At this critical stage the features are:

  • deepening cyanosis, within 24 hours of birth
  • breathlessness
  • progressive metabolic acidosis
  • if there are no associated lesions there is no cardiac failure and therefore have not got hepatomegaly
  • there are no characteristic murmurs

There may be a loud second heart sound because the transposed aorta is positioned anteriorly, next to the chest wall.

If there are additional lesions, the most common of which being a VSD, then cyanosis will appear later. This is because the additional lesion allows mixing between the two vascular circuits. These babies may develop signs of cardiac failure.