Transposition of the great arteries (TGA) is a type of heart
defectthat your baby is born with (congenital). In this condition, the two arteries that
carry blood from the heart to the lungs and body aren’t connected as they should
be. They are reversed (transposed).
In TGA, the following occurs:
- The aorta is connected to the right
ventricle. It should normally be connected to the left ventricle.
- The pulmonary artery is connected to
the left ventricle when it should normally be connected to the right ventricle.
This means that:
- Oxygen-poor (blue) blood is sent to
the body instead of to the lungs.
- Oxygen-rich (red) blood returns to the
lungs instead of going to the body.
This is the opposite of a normal
Babies can't live with this
condition unless they get treatment.
TGA may occur on its own. Or your
child may also have other heart problems in addition to TGA. These might include
blockage of blood flow from the right ventricle to the aorta, or variations in the
course of the coronary arteries. Other heart problems such as holes in the walls
between the upper and lower chambers of the heart (atrial or ventricular septal defects)
may allow some oxygen-rich blood to be sent to your baby’s body. Also, some parts your
baby's heart may stay intact to allow oxygen-rich blood to reach your child's body.
Normally, these connections would close shortly after birth.
Common heart defects that can
happen with TGA include an opening in the ventricular septum, called a ventricular
septal defect (VSD). This is a hole between the 2 lower chambers of the heart. This
allows oxygen-poor and oxygen-rich blood to mix