Are there surgical precautions for Neaurally Mediated Hypotension?

[espressochick]

I was told years ago that I had a miscommunication between my heart and my nervous system, now referred to as Neurally Mediated Hypotension.  I have always upped my salt and water intake and been ok.  Recently, at 40 years old and 130 lbs. and otherwise good general health, started with chest pains upon exercise and was ordered to take a stress test in which I failed due to my ventricle not getting enough blood flow.  I was immediately ordered for a heart caterization which found no blockages.  I had never undergone anesthesia prior to that procedure and had trouble coming out of it.  When they tried to have me sit up, I immediately had severe head pain, my blood pressure dropped significanty, chest pain, vomiting, numbness in my extremities and face, couldn't catch my breath.  They gave me morphine and could not figure out what caused the attack.  Could my reaction been because of the NMH?  If so, what can I do to prevent it as I now found out I have to have a hysterectomy in the near future, but do not want to undergo another surgery until this is figured out.  I am looking for any information that could help me.  Thank you