Spaying a Kitten with an Enlarged Heart

NEWLYWED2006 asks: "We have a kitten that we believe to be about 7-8 months old. When our vet did the pre-work for having her spayed, she found that the kitten's heart was enlarged. We had a heart scan done by a specialist and that vet told us she "should be fine" for the surgery. We are really nervous about it. She is an inside cat and there is no way she can get out. Her heats are a little annoying but not bad for us. She seems to be uncomfortable, though. Is there any risk or harm to not spaying her if pregnancy is not an issue? Is there any kind of procedure that might be less risky?"