Hi and Welcome 
to HealingWell, Bugsy!! 
That's quite a loaded question. 
I'm not quite sure of what to say...
I have heart failure, but I'm 53 and I've had children that are both almost grown now. Though my sister is your age and has 3 children, her youngest being just a year old now - she gets very worn out and she doesn't have any heart problems!
This could be very wearing on your body with the stresses it would put on it both during and afterward the pregnancy. However with all that said, each of us is an individual and I believe though the end decision is between you, the father, and your Dr.
I wish you all the best, Bugsy!!
Hugs, Teri