Figure 1

ATP load cardiac CT protocol. ATP was infused over 3 minutes at a rate of 0.16 mg/kg/min. 100 ml of contrast medium was injected at a rate of 5 ml/s and followed by 20 ml saline. Scan delay was detected with bolus tracking method at descending aorta, and we set up the delay time for five seconds longer than usually scan to fill the myocardium with contrast medium.