In an attempt to get a specialist referral for what I thought was POTS, I did a 30-minutes poor man's tilt test (i.e. lay down for 20 mins, took my HR and then stood up).
My laying-down HR was 73 bpm. By 10 mins, it was 92. It kept going up and was 106 at 30 minutes.
According to the POTS criteria, your HR has to go up 30bpm above baseline within 10 minutes and mine didn't. On the other hand, is it normal for it just to keep going up and up? It was 35 bpm above baseline after 30 minutes.
I don't feel dizzy on standing but I do find sitting and standing difficult and have to lie down for 15 minutes in every hour because I get exhausted, even if I'm just sitting with my feet up. I find standing more tiring than walking, a classic OI symptom.
POTS? And if not, is that heart rate pattern remotely normal?
umm is that heart rate pattern normal or not if it has a delayed response and keeps increasing.. I myself dont know.
*note some doctors/researchers test for POTS over a 12 min period and not 10 min.
20mins lay down time if you were relaxing, should of been plenty for most to then do a test from there (its just a case of making sure the heart rate is stable before starting the test.. some autonomic specialists only have people lay and relax with eyes shut for 10 mins before testing.. I personally find that my heart rate dont always stabilise in 10 mins thou does much of the time).
I do suggest to do the poor mans POTS test on a few more occassions in your case (making very sure you arent wiggling toes or moving), as sometimes POTS may not show and other times it may (it may not always be consistant).. and I dont know if that increase after that amount of time is normal or not so suggest to do it again (maybe at a couple of different times of the day or on one of your worser days). Stop the POTS test at the 12min mark. (if you are testing for BP problems thou, standing test needs to be longer)
There is also several different kinds of OI issues.. so thou you may not have POTS causing the OI.. you could have one of the BP OI issues. One thing about POTS I like, is that unlike CFS it is testable and if you have it, it should show up. If you cant see POTS on your poor mans tests, I myself wouldnt suggest asking a doctor for a TTT for suspected POTS. (Ive never had a TTT but find my heart rate does up to a 67 beat per minute increase on poor mans test as long as I havent been sculling a lot of water just before the test to ward off the symptoms). Maybe a TTT thou would be good to look for other orthostatic issues.