Hi, Claire,
I've now had two angiograms, one at Papworth Hospital 10 years ago with access in the groin, and one three months ago at The University Hospital Coventry with access through the wrist (infinitely preferable!). The procedure has come on a fair bit in ten years! Neither was too traumatic an experience... uncomfortable rather than painful, and in both cases the staff were extremely kind and helpful, and everything was fully explained.. no nasty surprises. Tell them you are Type 2 from the outset, and I'm sure they will take this in their stride and make allowances for your dietary requirements. People differ, of course, as do the preferences and working practices of consultants, but my recent procedure involved admission at 7 a.m., and I was home again by mid-afternoon. Be prepared for a lot of sitting around doing nothing... take a good book, DVD player or what -have-you to pass the time. If they decide to do an angioplasty at the same time, you may be in overnight.
Don't worry! Its really not that bad. Good luck.