Hi Lisa,
So sorry that your son needs heart surgery. It's awful enough for adults, but horrible when young children have to go through that.
I just saw your question and wanted you to know that MedHelp also has a Pediatric Heart Forum where cardiologists from the #1 Heart Center answer questions every day for free. I hope you'll go over there and post your question for them. They are amazing and they helped my sister, when my niece had heart problems.
Here is a link:
http://www.medhelp.org/forum_disclaimers/show/340
You'll have to agree to the disclaimer, etc. but it is well worth it! If that link does not work, then just click on Forums at the top of this page; look at the alphabetical listing under "Ask a Doctor" and click on PEDIATRIC HEART. You should be able to get there.
Good luck to you and to your son.
Pam