Matt - aren't tingles in (especially) the left arm one of the possible "heart attack" warnings? How old are you?
I was thinking the same thing

Matt the amitriptyline are fine they take a little while to get into your blood stream, depending on the dose you have been given I would be carful as high doses near on knock you out they stop the nerve pressure though, I have them for my neck/back.
only down side I found when I was on them was I hated getting up in the morning and was a little knarky first thing. I only take/took them at night to stop spasms in my back
I have not had to have any for over a month or 2

(I touched wood)
Hope you get it sorted soon fella

Ian