Thanks for all the reply’s/advice. I see both an EP and a neurologist. I put in a call to the EP and he seems to think it may be a rebounding effect from the beta-blockers I take during the day. I also mentioned it to my pain management doctor (I also have fibromyalgia) and he seems to think it could be a response to pain during the night. I had multiple tests done upon diagnosis including a holter, stress test (I couldn’t even stand on the treadmill let alone walk before my heat rate was in the 190’s and I almost passed out), a nuclear stress test, echocardiogram, 24 hr urine test, and tilt table test. The EP is confident my heart is healthy. I had an 9cm pheochromocytoma removed about a year before the POTS diagnosis. I was dismissed and told it was just anxiety for a few years before a doctor finally took me seriously and tested for the pheo. My neurologist suspects that because I had the pheo for so long, it caused my autonomic nervous system to go haywire.
My POTS symptoms are pretty well controlled with medicine during the day. I just wish I could get it under control at night so I can get a good nights rest!