Hi! I have a heart shaped uterus as well... its called a bicornuate uterus ( i think thats the way its spelled). I finished my first complete ivf cycle on june15th and am now pregnant with twins.
The main problem with this type of uterin anomaly is that the baby grows in just one side or "horn" or the other. My first child was conceived naturally and the only issue was that she was 6 weeks premature. ( perfectly healthy otherwise tought).
anyway, I think you will and should be considered higher risk for premature labor but otherwise you will probably be fine.
My twins are growing in the left horn and other than being on limited activity and being watched a little more carefully .. everything else is normal.
Years ago when it was first discovered that i had this... i was told i would never be able to carry a baby to term... luckily that doctor was wrong. of course that was 18 years ago when i was a very young teenager!

Good luck! I hope I have helped. There is also all kinds of info available if you do a search on a bicornuate uterus.