For the stress part of the examination, you will exercise by either walking on a treadmill or pedaling a stationary bicycle for a few minutes. While you exercise, the electrical activity of your heart will be monitored by electrocardiography (ECG), and your blood pressure will be measured frequently. Before you stop exercising, you will be given the radiopharmaceutical through a line leading into a vein in your arm. The compound is given when the blood flow to the heart is at its peak caused by your exercising. This provides the best opportunity to identify regions of the heart that are not receiving adequate blood flow.
One minute later, you will stop exercising. Approximately one half-hour later, you lay on an examining table, and the gamma camera will then be used to obtain images. The gamma camera will move slowly and automatically in an arc over the front of your chest after it is positioned initially by the technologist.
The images obtained after exercise must usually be compared with images of your heart obtained after injection of the same radiopharmaceutical while you are resting. This may be performed before or after the exercise part of the examination, depending on the protocol used. Comparison of the exercise and resting images is done to determine whether coronary blood flow has changed once you have rested, and to help evaluate for coronary artery disease.
If you are unable to use a treadmill or bicycle, you will not exercise but be given a drug that will increase the blood flow to your heart, as if you had exercised. You will then be given the radiopharmaceutical.
Immediately after the procedure, the technologist will check the quality of the images to ensure that an optimal diagnostic study has been performed.