Hi Sleepy237,
I have had a tilt table test about 10 days ago. Francelle is right, you do need to stop any meds prior to your test (in conjunction with your doc's advice) like florinef & beta blockers as they will interfere with the results. You should hopefully get some info on prep prior to the test though. I had to fast (no food/water) for 4 hours prior to the test.
My tilt table test was at 60 degrees, protocol is anywhere from 60-80 degrees but it obviously depends on what the hospital/clinic does. Good luck & make sure you get someone to drop off/pick you up from the hospital. I also brought a snack with me for afterwards & a bottle of rehydration mix which helped. Prepare for some PEM/payback for a week or two afterwards.
Depending on which Tilt table protocol the hospital/clinic uses they usually tilt you up to 60-80 degrees and then leave you there for approximately 20mins. If you have not had a significant response by then, they may then give you a drug to induce a response (a vasodilator or something similar) and then observe you for another 20mins. See this article for different protocols and what is involved
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1513525/
The tilt table test should last at least 30-45mins as some patients dont respond until the 30-40min mark (pass out). If you do faint or have an adverse reaction which is intolerable for you they can stop the test at any time. A doctor should also be supervising the test just incase.
I also have just been diagnosed with joint hypermobility syndrome by my GP, autonomic dysfunction can occur with this condition due to the connective tissue problems.
I wasn't aware that a pacemaker was a viable treatment for POTS but I may be mistaken. This is a great website regarding studies, testing and treatments
http://www.dinet.org/
Presently I am waiting for my TTT results and then will get a referral to a neurologist who specialises in dysautonomias. From what I take it, POTS & dysautonomias are rare and not well known of, so not every cardio or neuro is well equipped to help you. Patients also get misdiagnosed with anxiety disorders unfortunately due to complaints of racing heart etc.
My GP has started me back on a low dose (10mg) beta blocker to keep my max heart rate down which is helping. I am also looking at trying fludrocortisone to help with fluid/salt retention. Basically the treatments may involve stopping/reducing the tachycardia, increasing vasoconstriction or increasing blood volume/fluid retention. Treatments do depend on what type of POTS you have (partial dysautonomia or hyperadrenergic). There is info about treatments on the above website too. This is also a good website with links to full text articles
http://www.dynakids.org/resources.jsp
I was anxious too about my test. It is an unpleasant experience, but very helpful for your diagnosis. When your cardiologist looks at the data they should be able to diagnose a positive tilt test based on either a POTS response, orthostatic hypotension or autonomic failure. If you see the tilt table test article
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1513525/ there is a table in it which lists the kinds of positive responses.
In terms of what my test was like personally. My heart rate went from around 80bpm lying supine to over 150bpm (this is what the supervising doc reported when I asked). I had chest pains/discomfort, headache, nausea, tingling in my feet, feelings of being hot & sweaty (even though the room was aircon), feeling dizzy and light headed, and general fatigue/exhaustion. I did not faint however. My test was on the 28th of April and I still feel like I am recovering from it.
Good luck with your test and feel free to ask any more questions.