So, I have lost a few lbs, and I am 5 weeks out of surgery. I am experiencing a slow heart rate of about 42 while lying flat and 51 while sitting up.

anyone else having this issue??

I think you need to call the surgeon.

Are you on any BP medicine? I take Bystolic for BP and that is one of the side affects.

Before I went for a heart cath last year, I was on metropolol (spelling?)--a beta blocker. Turned out all my heart problems were related to that medicine. It lowered my pulse rate between 32-35 beats a minute, I had chest pains and episodes of nearly passing out. My cardiologist thought I had a blockage. It was due to that medicine. As soon as they took me off of that prescription drug, my heart rate returned to normal and I felt so much better and the chest pains ceased. My heart cath (angiogram) showed no blockages.

If you are not taking any of those heart medicines, recommend you see a doctor ASAP. Or if you're taking any of the medicines, see the doctor anyway---you may need to downsize your dosage or there may be some other underlying problem. A lot of those heart medications including the beta blockers have to be weaned off of to prevent other problems, so please see a doctor before you do anything like stopping your medications.