There is a website called www.amothersheart.org where you will find many people who have dealt with this type of thing.
I am 32. When Cardio discovered in Dec. 2006 that I had Mitral Valve Prolapse with mild regurg, he told me that my baby-making days are over as I will not survive another pregnancy and if you do decide to get pregnant, then you ARE NOT ALLOWED to give normal birth.
In my opinion your cardiologist is copping out. ask him/her in another way, like "what can happen if" vs a flat "will I survive". Doctors dont like to answer that kind of question.