i also wanted to say that (assuming you are 25 yrs old) that is very low risk for downs indeed, so dont stress too much about that.
having an AVSD does not necessarily mean that you child will have any other problems. the condition is compatible with life and your baby will most likely need some surgery. the reason they did the amniocenteris is becase heart defects such as this are often associated with congenital syndromes, such as Down syndrome for example. I am not implying at all that your baby has this, and even if baby did it would have been picked up on the ultrasound scans you had. the amnio will look for downs and lots of other syndromes so that the doctors know what they are dealing with. if the heart defect is just on its own, then there is no reason at all for baby to have any long term poor outcome. other than being a little cyanosed, they will be fine in good hands. if you are this concerned i strongly suggest you ask to see some one earlier as it must be very difficult to have this over your head.
billy
(2 weeks to graduating from med school)