Structure of a Heart with Transposition of the Great Arteries (TGA)
In transposition, the pulmonary artery and the aorta are switched, or transposed. So they come off the opposite pumping chamber. What that means is that the blue blood comes back to the right atrium, to the right ventricle. But now, instead of going to the lungs, it goes back out to the body. So you have blue blood going in a circle. It never picks up oxygen.
Oxygenated blood from the lungs then returns to the left side of the heart, comes from the left side of the heart out to the pulmonary artery, goes to the lungs in a separate circulation.
This creates what we call a "parallel circulation."
Topics Covered: Transposition of the Great Arteries
Related Centers and Programs: Cardiac Center