Hiya, sorry to hear you are experiencing these symptoms.
MVP does seem to have a tendency to run in families and be heriditary so if one of your parents has this then you may be at risk of inheriting this also, but it is not to say you will inherit this condition.
You say you have had Mono, this itself can cause dysautonomia. Several other conditions can cause the symptoms you mention and these should all be ruled out before a definate diagnosis of dysautonomia is made. It is good that you are going for further testing and hopefully you will get some answers.
Sorry you are dealing with this. My 15 year old son also has dysautonomia, he hasn't been to school in over a year. They believe his is hereditary. My 18 daughter has symptoms, but she is quite functional, and when I was young also had many symptoms(never diagnosed). My son also has motility issues, gastroparesis, also. Everything else, intestinal wise, is working fine.
He dealt with migraines for over a year, and then they stopped(pain wise). They believe he is now having silent migraines, which is giving him nausea everyday.
It definitely can be hereditary.
Sorry, I forgot to mention a couple of things. I don't drink alcohol, smoke, or have caffeine and I'm not particularly stressed and I'm getting enough sleep (causes of PVC's). I can tell when I'm having the PVC's and bigeminy because I get short of breath. I have been on amitriptyline and nortriptyline.