Just wanted to chime in that I have had a similar issue with heart rate (not exactly the same). For some reason, my normal at rest heart rate is 80bpm, but when I am standing it shoots up to 100. My neuro discovered this as I pressured him into figuring out why I get extremely dizzy when standing but not when sitting or lying down.

This did kind of worry me that it went up 20 points just from sitting to standing... I know it's still in the range but I was a bit concerned as well as that doesn't seem like it would be something that is normal. I'm not a doctor by any means, but i find it strange that it goes up that high and I also have dizziness when standing...