The MAJOR defects are:
1)The so-called 'single ventricle defects' are hypoplastic LEFT heart and pulmonary atresia (AKA hypoplastic RIGHT heart)
2)Transposition of the great vessels (aorta and pulmonary artery reversed)
3)Tetralogy of Fallot (over-riding aortic arch, rv hypertrophy, VSD and pulmonary stenosis)
4)Patent ductus arteriosus
6)TAPVR (total anomalous pulmonary venous return)
7) truncus arteriosis
8) aortic stenosis and interrupted aortic arch
If you go to The Chidlrens Heart Institute >> here>> Home
> scroll to the bottom of the home page and click on the 'heart house' link. It contains a really understandable introduction to these and many more defects, using a model of a house as a visual aid. The chambers are rooms, the valves are doors, and the blood flow sidewalks around the house. I refer parents to this site a LOT.
Oh, and there really are about a hundred ways you can be born with a jacked up heart. It's amazing.