Cardiolite Stress Testing
During a nuclear stress test, first you will be injected with Cardiolite, a radioactive tracer, in the vein of your arm or hand. Cardiolite is taken up by the heart muscle through the coronary arteries in proportion to the blood flow to it. This material should not affect you in any way. It is then necessary that you wait between 20 and 45 minutes for the tracer to circulate to the heart. You will be instructed where to wait and given water at this time. You will then be placed on a special chair (similar to a dental chair) and a Nuclear SPECT (single-photon emission computerized tomography) camera will travel across your chest to obtain the rest images of your heart. This takes approximately 15 minutes. It is necessary that your arms be placed above your head during the cardiac stress test.
Next, you will be moved to a stress room to continue your study. Electrodes will be placed on your chest, similar to an electrocardiogram (EKG). Your blood pressure, heart rate, and EKG will be monitored and recorded by an attending nurse.
You will be asked to perform a "graded" exercise test on a motor-driven treadmill. The first stage will begin with the treadmill at a slow speed and a slight uphill inclination. Every three minutes the treadmill will increase in speed and elevation. The nurse may stop the test at any time for medical reasons or you may stop the test because of significant fatigue or discomfort. In general, however, we encourage you to exercise as long as possible in order to maximally stress the blood flow to your heart.
About 90 seconds before you need to stop exercising, a small amount of the radioactive Cardiolite will be injected into your bloodstream through the IV line and allowed to circulate during the final minute of exercise. The nurse will monitor your heart rate, blood pressure, and EKG for several minutes following the exercise.
You will then be instructed as to when a second set of images will be made of your heart. This can range anywhere from 15 minutes post-exercise to 3 hours post-exercise, depending on the schedule. When you return, a second set of images will be made in the same way as the first set of images and will also take approximately 15 minutes.
When both sets of images are completed, the Upstate Cardiology physician will have a view of your heart at both rest and stress. Even though it may be hours after exercise for your "stress" images, the isotope entered your heart at maximum stress and will remain there until images are completed.