Thanks again for your help en bloc. The reason why the inflater cuff registers errors is because my blood pressure is changing during the measuring process. I suspect the errors are the result of the diastolic registering as being higher than systolic because the systolic is measured in a trough and diastolic at a peak. This has resulted in implausible readings like 160/60 and 110/100 where in the gap between measuring the diastolic and systolic my blood pressure is changing. It is extremely labile during the period of testing. My blood pressure drops last a second or two before bouncing back with an brief hypertensive overcorrection. I can sustain the blood pressure drops for an extended period if I initiate a trigger such as standing up and maintain the trigger with a sustained unstable posture. Of course the doctors assumed the errors were as a result of my arm moving or flexing and fouling the test. This is not the case, I am acutely aware of this issue and make sure I don't flex or wave my arms around during measuring and keep it steady during inflation.

I do however, during attacks, experience a more orthodox OH where my baseline blood-pressure drops, and I experience dizzy spells, accompanied by comparatively mild POTS. I'm pretty certain my OH, whilst as you say is a little outside the box, is simply a result of my being fortunate that I require a little more orthostatic stress than usual to trigger a drop. So for instance I just measured my BP and it was 140/80 seated 145/90 after standing( probably a bounce back overcorrection) and 105/70 after walking up the stairs. I had a 15bpm increase on standing despite such a highly transient bp drop. Similarly I can stand at the washing up sink fine, but when I start moving my arms around to perform the task my blood pressure starts bouncing around. I should of course be grateful for the improved functionality of this but it certainly has made diagnosing it a misery.

The beta blocking incident occurred before the IST diagnosis as a result of the assumption that my tachycardia was a psychiatric issue having discounted the blood pressure issues. I was beta blocked to 60 bpm with the sort of beta blockers used for psychiatric problems. Following the IST detection I was beta blocked using a very small dose of bisoprolol and only down to 90bpm, which I was able to tolerate and provided some relief, although it works against me when I'm bradycardic. I have never had panic attack like symptoms. Just a highly stable 110bpm the highest resting heart rate was around 130bpm with rare very unpleasant chaotic attacks with wildly fluctuating BP and heart rate. This is an extremely hair raising experience and at times I have had to lie on the floor and elevate the legs to maintain consciousness and I just take 300mg of aspirin and hope for the best. I'm not sure I share your opinion of my medical care to date. There is no excuse for detecting a resting heart rate of 110 and it taking 5 years to get a referral to a cardiologist. A patient shouldn't have to purchase his own cardiac monitoring equipment, study autonomic neurology, and correctly diagnose himself to convince a doctor that a resting heart rate of 110 warrants a referral to a cardiologist. Since the IST was detected I have a better relationship with the medical profession but I am still wary of undergoing testing that could throw up misleading results. Once bitten twice shy, and I think you can see how my blood pressure issues can circumvent standard testing.

I don't think my gasping is quite the same as yours Nervous1, although I know exactly what you mean. I am aware of the nature of the inspiratory gasps because they occur whilst I am still awake. They are not me waking up with a start. I am breathing normally and I will suddenly take a sharp involuntary intake of breath. This is a very common symptom with MSA as a result of the brain failing to detect breathing - the reverse of central sleep apnea. I have also had episodes whilst asleep where I wake and take an absolutely vast lungful of air similar to if you exhale far beyond your normal cut-off which I suspect is a failure to shut off the exhale reflex. These are concerning symptoms as as far as I am aware they are closely associated with CNS autonomic dysfunction. I would be very pleased to here from anyone experiencing this particular symptom with a non CNS diagnosis. Perhaps I should take this particular issue elsewhere.

Thankyou so much Nervous1 for sharing you personal experiences. It really helps to hear others experience and cross-reference with my own. Its interesting to note autonomic disruption not associated with dysautomnia, there were autonomic components of PTSD cases I've come across.

I very much appreciate your input on the AAG testing en bloc. I think as a result I will go ahead with them. It is precisely the sort of input I was hoping for. It is a great comfort to have a place to go with my queries. I'm sorry if I come across as somewhat prickly at times, its been a very frightening, isolating and frustrating few years and just talking about it takes me to a very painful place.