(See Normal Heart Image for comparison)
Click image to see download options from Flickr:
1- Oxygen-poor blood coming back from the bottom half of the body is diverted directly into the lungs with a conduit instead of flowing back into the heart before going to the lungs
2- Fenestration – a small hole in the conduit just in case there is too much pressure going into the lungs. This gives the body time to adjust to the new circulation.