Ann
You said that your HR was up to 82 one evening. Does that mean that it is in the 70's the rest of the time? If so, then perhaps there isn't much need for concern, if it was an isolated elevated reading....My surgeon seemed to think that even if mine was in the 70's he'd of been happy enough, and I'm a couple of years younger than you!!
Before my 1st surgery (2001) my resting HR was 67. After surgery, when all had stabilised it was 62.
After my recent surgery a few months ago, I was on 25mg of atenolol, twice per day. (and a 4mg ace - perindopril/coversyl). My resting HR was somewhere in the low 50's.
At my post surgery review, my surgeon recommended that we try other alternatives to the Beta, to get my BP below his reccommended target of 120/80.
So my doc took me off the Beta gradually and retested my BP after being on the 4mg Ace (only) for 4 weeks. At this appointment my BP was around 124/85 or so. My HR is around 60/62 I think.
So at my request, we are now trying 8mg of the Ace daily, to get the BP a little lower. If that doesn't work he may add in something else.