Your claimed HR is normal, even low-normal, for someone rising to void and then getting back into bed. I have been a runner/snowshoer/cyclist all my life, and my HR will go to 90 just getting out of bed. I am somewhat reactive, obviously, but I'm soon down into the 60's or lower. Prior to developing atrial fibrillation, my resting HR was in the 40's. Post catheter ablation, two of them, it is about 62 seated or any length of time. So, there is something else going on. A pounding heart might be an arrhythmia, or it might just be an adrenergic response...except that those typically come with an elevated HR in the 90-130 range.