To add - had one done two months ago - no food 4 hours before test - stopped taking beta blocker and metformin that morning - - one hour prep time to stabilize BP and heart rate - 15 minutes in an air conditioned room - slight warm feeling when dye injected - machine makes more noise than I expected - drove home 30 minutes later.
I've had one also...can't add much more than DeltaDawn23 did though. I had no problems with the dye and it was a pretty quick test, but I didn't have to fast before mine - maybe because I was in the hospital already.
Yes, I had one this spring. It was very simple, took an hour tops. I had to fast for 4 hours, take a beta blocker to bring my heart rate down -- they want it in the low 50's. They took one picture, put in an IV and injected a contrast dye and took another picture. The contrast dye is the same one they put in when you have a kidney x-ray, it is iodine based. It gives you a somewhat unpleasant warm flush feeling for a short time, maybe 1 minute. I needed to make sure I had no blockages in order to try a new drug for my Afib. I had a heart cath 7 years ago and it was good, but they wouldn't let me try Rhythmol until they knew I was still clear. The coronary CTA is the way to go, much less invasive than the cath, way cheaper too. $1200 for the CTA vs $12,000 for the cath (and that was 7 years ago) -- it's sure to be way more now. It was definitive for what my doctor needed and less risk. Good luck with it.