My dog has to get an eyelid tumor removed but he has a heart murmur?

we just found out that my dog has a tumor on his eyelid and he has a slight heart murmur. he is a miniature poodle and he is about 9 years old weighing about 10 pounds. The vet told us that putting my dog on anesthesia could be dangerous due to the heart murmur, but he has to get it done in order to get the tumor removed. I was wondering how risky this operation is. Is there a possibility if i lose my dog during this operation? Will he be the same? I love this dog so much and i am really worried. We are not sure if its cancerous yet. I want straight-forward answers (preferably from specialists). I cant get my mind off this. I love this dog and i would like to know if he can push through this

A murmur is just the sound a heart makes. So, the way a Cardiologist explained it to me is the number of the murmur 1-6, only means how loud it is. So, imagine 2 radios playing at the same time, both playing the same song, only 1 is low and the other loud. Whether he will push thru or not, will depend on the general health of your dog. I had a old rescue dachshund that had a heart murmur and lived to the grand old age of 17.