Nuclear Stress Test - Exercise

The purpose of this test is to determine the blood flow to the heart muscle when the heart is under stress (exercise) and at rest.  Before exercise, a small intravenous (IV) line will be started in a vein in your arm or hand.  The IV will allow us to inject the Cardiolite marker into the bloodstream at the appropriate time. 

What will happen during the test?

First you will be injected with a radioactive tracer, Cardiolite, into the vein of your arm or hand. Cardiolite is taken up by the heart muscle in proportion to the blood flow to it through the coronary arteries. This material should not affect you in any way.  It is then necessary that you wait between 20 – 45 minutes for the tracer to circulate to the heart.  You will be instructed where to wait and even 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 this time.

Next, you will be moved to a stress room to continue your study.  Electrodes will be placed on your chest the same as for 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 increases 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 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.

What is the preparation for the test? 

• Do not eat or drink anything past midnight the day before your test.
• It is very important that you do not have any food, beverages or medications that contain caffeine 24 hours before the test.   Remember, this includes chocolate.
• Wear loose, comfortable clothing and comfortable walking shoes.  Do not wear boots, jumpsuits, overalls or a dress.
• You should continue to take all medications (up until midnight the day before test), unless your cardiologist instructs you otherwise.

What should I bring with me to the test?

• Inhalers, if you use them
• All medications in their original bottles
• Insurance card
• Referral for Cardiolite Stress test if required by your insurance company

Once your appointment has been scheduled, it is very important that you notify us if you are unable to keep your appointment. Please notify our office at least 24 hours in advance if you are unable to keep your appointment.  We would appreciate this notification due to our tight scheduling restrictions.  Thank you for your cooperation.

What is the accuracy of this test?

In general, the diagnostic accuracy of the standard EKG stress test is about 68% and may therefore provide limited information.  This accuracy is further diminished in some patients because of certain medications, abnormalities on the resting EKG, etc.  The more sensitive Cardiolite test is very useful in these instances and provides what we call a physiologic assessment of blood flow.  In addition, the Cardiolite test provides very useful information about your risk of having a heart attack.  Although no test will always provide 100% accurate information, the presence or absence of a significant blood flow problem to the heart muscle can usually be documented with this test.

Who will give me the test results?

After a review of the test, your medical history, other imaging modalities and previous tests by an Upstate Cardiology physician, a report will be sent to the ordering physician.  The ordering physician will then review the results and discuss them with you.  If you are an Upstate Cardiology patient, your physician will go over the results with you at your follow up appointment time.