In terms of delaying the
surgery--judging from what you have posted--the worst case scenario would be that your heart
rate would just get slower and slower, you'd faint more often with less control over it, and you'd be so tired that it would be hard to do much of anything.
So, major things to think about are 1) how well you feel and function every day, 2) the serious risks involved in fainting, and 3) medically speaking, whether or not you have any kind of "heart block'?