Hello,I ve read conflicting instructions about nuclear stress testing. Some have 12 hours no caffeine and some 24, which is right? How will this effect test? Also, I am a smoker. I wasn t told I couldn t smoke. Will that have any effect? And lastly what exactly is going take place as far as taking this test? What should I prepare for? I read that a camera will be used, how??!! My test is at 8 am tom morning if you could please advise me before that I would greatly appreciate your help ....Thank You!!!