My symptoms are basically all you can think of. Other then the rapid heart rate upon standing, I also have headaches, pain for no reason, heat intalurance, lightheadness, dizziness, completely fainting 4 times in the last year(most time I can stop it before it happens), inability to lose weight(I've been going to the gym 5 days a week for 1 1/2 months now and haven't lost anything, nor has my heart rate gotten any better), chest pain, feeling of my heart beating too hard, feeling that I am on heavy medication such as morphine or something. Not all of these occur at the same time, but enough to make me feel lost in my health. When I first started having symptoms I was 15 and in ROTC. I was always walking around or playing kickball, basket ball, ect. I'm not as active now because I have 3 kids 5 and under and because of my symptoms.
In normal people deconditioning can cause you to have an elevated heart rate when you change position. Which may explain your thought that you had a positive ttt. HOWEVER, in people with a dysautonomia, be well conditioned won't stop your heart rate from elevating when you change positions. Regular exercise may help regulate your heart rate (in SOME people with dysautonomia) a little bit but alone it likely won't ever stop the problem.
I was told that I was just deconditioned before I was first diagnosed many years ago as well. I was an active 12 year old kid who had been running and climbing and jumping with my friends on a daily basis, so the diagnosis of being deconditioned simply didn't make sense for me and my mom pursued it further. It wasn't until we went back and explained the situation further that the doctor released that this was more than being simply deconditioned.
If you exercise regularly and you're not seeing any improvement at all then it's time to go back to the doctor and explain that it just isn't getting any better.
Well, I'm not a doctor but I am a mom to four kids with dysautonomia. People don't normally pass out during a TT-hence a positive or a negative test result. I can't diagnose you but I can tell you that my hubby and kids have had positive TT. Are you having any symptoms? What made the doctor do a TT to begin with?
Also keep in mind that while there are some good doctors out there, they DO make mistakes and 'deconditioned' can sometimes be doctor speak for "I don't have the foggiest idea what's wrong with this patient."