I'm a bit more clear now on your BP. I'd still suggest the stress test as I think your heart function needs more investigation and the BP and heart rate can be closely monitored...and a doctor is always present during the entire test and therefore could see first hand what is happening and not be able to dispute the findings.

Trust me, I have no illusions about how frustrating and unpleasant medical care can be. It took me 12 years to be properly diagnosed with neurologic complications of Sjogren's. I had a collection of various autonomic dysfunctions, PN, weakness, joint pain, and numerous other symptoms and separate diagnosis, including strokes, open heart surgery...the list goes on. I was bounced around from doctor to doctor, including the Mayo Clinic. No one could figure out the one component that was causing everything...because my labs for autoimmune disease are sero-negative (now I know that 40% of patients fit in this category). It wasn't until I went to Johns Hopkins for a consult about my antiphospholipid syndrome (APS) and 3 strokes that a doctor sat with me for 3 hours reviewing my extensive history. He ended saying, I think you have Sjogren's and that it's attacked your nervous system. A lip biopsy confirmed his thought, and a special MRI/MRN confirmed the damage to my dorsal root ganglia. 12 years it took for that first test to put all the pieces together! I assumed you meant the beta blocking experience was after your IST diagnosis...which would have been an appropriate treatment. I'm on the same page now.

I'm curious about your OH. What happens after you stand for 2-3 minutes? After 5-10 minutes? How low does your BP go? If your BP goes back to normal after standing, then how long do these attacks last? Is the worst of the attack during the labile BP or low BP? Do you experience any chest pain/discomfort during these attacks? If so, describe it, please. I ask because I wonder if you're experienceing any cardiac vasospasms? This is yet another autonomic dysfunction that can occur and can greatly affect your BP (both high & low) and heart rate. Also, do you have any unusual skin discoloration (particularly when cold)...a lacy pattern of blood vessels. It's called livedo reticularis. If you google images, you'll see what it looks like. It also a sign of blood vessel spasms (in medium blood vessels of the skin)..and of course an autonomic dysfunction. They are not widely spoken of, but most definitely an autonomic dysfunction. The cardiac vasospasms are difficult to diagnose, but an echo stress test may be helpful if they see any heart wall dysfunction, absent of severe CAD.

BTW, I have experienced the gasping upon onset of sleep. I too am still actually awake and realize it happening. My pulmonologist says it falls in the category of central sleep apnea and directly related to the dysautonomia. He said, in central apnea, the brain forgets to breathe. Have you had a sleep study done? Mine thankfully is a rare occurrence, so would likely be impossible to document on any given night. When mine occurs, it is also in waves for a couple days or even several times on the same night...sometimes waking me up with the gasping.

Is there anything you can think of when this began that might help lead you to the cause...it sure would make diagnosis much easier if you knew what brought it on. Was the onset sudden or gradual? Did it occur right after the flu bug you mentioned? What about taking any antibiotics or around any unusual toxins? If this began suddenly and after the infection, I would certainly consider autoimmune. Have you had any AI testing? Did you see an infectious disease specialist about the flu bug?