OK, given that it's that recent, I'd expected tiredness but probably not exhaustion, and would hope at the two month point post-surgery, you'd be more recovered.
Have you received guidelines about a heart healthy diet?
I'm not familiar with the term "1 1/2 post".
If your exhaustion is not from activity but simply from existing (while sitting or lying down), that does not sound normal at all to me and should be reported (if the implant was via a general anesthetic and more than 24-48 hrs ago).