No special preparation is necessary in advance of a cardiac CT examination. You should continue to take your usual medications, but should avoid caffeine and smoking for 12 hours prior to the exam.
You should wear comfortable, loose-fitting clothing to your exam. You may be given a gown to wear during the procedure.
CT scanners use x-rays. For your safety, the amount of radiation exposure is kept to a minimum.
Women should always inform their physician and the CT technologist if there is any possibility that they are pregnant.