Does anyone else have issues with Bradycardia/Orthostasis?

Hi all,

So I've developed Bradycardia (my resting pulse is in the low 40s/high 30s BPM). I'm also orthostatic- my blood pressure drops significantly when moving from laying down to sitting to standing (sometimes I get lightheaded to the point of almost passing out).

I've been to several doctors and had extensive tests done, but all of my blood work comes back normal... so they don't have any advice for me... which is frustrating.

I'm definitely eating enough calories (around 1600)- and the intensity of my workouts doesn't seem to phase my symptoms.

Anyone have any thoughts?