I am unsure why the first link has been blanked out but this health page specifically puts vestibular incidence as a possible cause for POTS.
I believe I had read elsewhere speculation that certain types of autonomic dysfunction could cause certain vestibular problems, but not the other way around. Sorry, I can't recall at the moment where I saw that and can't seem to find it at the moment.
That was my first impression from reading various abstracts of information, but I have read in some that there can be vestibular causes of some autonomic dysfunction (I may be mis-percieving them - the lingo is only just becoming understandable!!!!) The first link above is specifically about POTS and gives vestibular conditions as possible cause, under their possible causes section they state the folowing:
''Ear vestibular problems
It is proven that vestibular disorders may interact with blood pressure and heart rate control. The vestibular system is a source of information about uprightness and the whole system is localized in inner ear.''
I have also read that:
''vestibular hyperacusis can affect the autonomic system and cause problems such as loss of consciousness, mental confusion, nausea, or extreme fatigue.'' (taken from vestibular.org website)
Vestibular Hyperacusis is a specific abnormal vestibular disorder. Although I have read that vestibular system can have effect over heart rate - I have not found anything that states in which context.
Also, I read:
''Research in collaboration with investigators at Vanderbilt University uncovered a vestibular sympathetic reflex in humans involved in blood pressure regulation.'' - http://pediatrics.med.nyu.edu/dysautonomia/about-us/history
I am not to good at the moment and am pushing through many symptoms including brain 'fog' so I could possibly be taking these in an incorrect context, but I will look further when I am feeling better.
I am probably on a massive tangent, I think if you look hard enough on the web you would find something that relates to everything!!!!!! (if that makes sense) xxx