The first question frequently asked is, "What is Nuclear Medicine?"  Nuclear Medicine is a medical specialty that has been practiced since the 1940's.  A Nuclear Medicine test has no greater risk than conventional x−ray procedures with respect to radiation exposure.  Nuclear Medicine tests require only very small doses of radiation, often lower than those associated with x−ray procedures.  The Nuclear Medicine team is made up of doctors, nurses, technologists and others.  Exercise or Stress Imaging is a common procedure; millions are performed in the U.S. each year.  It is a procedure that will provide your doctor with valuable diagnostic information about the flow of blood to your heart.  

This kind of imaging will help your doctor determine:

If you have a form of heart disease

If your heart is receiving enough blood

If you will need to have more testing

You will be asked to FAST (not to eat or drink anything) for at least four hours or longer before your exam.  Certain foods contain ingredients, like caffeine for example, which may interfere with the test.  Coffee, tea, colas (even "caffeine free"), chocolate foods, and some aspirin products all contain tiny amounts of caffeine.  If you cannot fast, are on medication, or are diabetic, ask your doctor for special instructions.  [Diabetes download form at the bottom of this page.]

You will need to temporarily discontinue certain medicines before the examination.  If you are taking heart medication, you should not take them the morning of, or the night before your test.  This is so it can be documented how well your heart works without the heart medicine.  Some medicines may affect the test results.  Be sure to notify your doctor of all the medicines you are taking.

On the day of the exam, wear comfortable clothes, a pair of sneakers/walking shoes and socks.  Comfortable, loose-fitting clothing will make the exam easier for you.  

If you are nursing or if you think you may be pregnant, inform your doctor before the examination.

You should have no food, coffee, or juice for at least four hours or more before the test.  (If you are diabetic or hypoglycemic, ask your doctor for special instructions; you may be asked to eat a light meal.)

Tell the nurse or technologist if you have any allergies, if you are pregnant or if you are nursing.

You will be asked to read and sign a consent form.

If you have any questions about the test, do not hesitate to ask the technologists, nurse or doctor.

Electrocardiograph (ECG) Pads will be attached to your chest to closely monitor your heart rhythm.  A small IV needle with tubing will be inserted into a vein in the arm.

Depending on the type of exam your doctor has ordered, you will either be exercising several minutes on a treadmill or you will be injected with a prescribed medication (adenosine) over a several minute period.  The purpose is to increase the workload being placed on your heart.  During your exam, a team of technologists and a doctor will coach you and closely monitor your ECG and blood pressure.  

If at any time during the exam you experience unusual symptoms such as shortness of breath, chest or arm pain, or lightheadedness, immediately tell someone on the team.

Near the end of the exercise or injection period, and depending upon your blood pressure and heart rate, the technologist will inject the diagnostic imaging agent.  The injected dose will travel throughout your body and will concentrate in the heart muscle.

You will then lie on  a table under a special large camera.  Several pictures of the heart will be taken using a SPECT (Single Photon Emission Computed Tomography) camera.  The SPECT camera rotates around you to obtain the images.  The SPECT picture takes about 15-20 minutes.  It is very important to remain still while the pictures are being taken.  Imaging will be repeated later in the day and possibly the following day.

Additional specific details regarding your exam will be clearly explained to you upon your arrival at the lab.


Thallium Stress Test: Thallium Isotope is used. 
You will be here for 1-1 ½ hours in the morning. 
You will be asked to return in 3 hours for the resting portion of the test, for about 15-20 minutes.
Pharmacologic Stress Test: Same as above, except you will also be injected with a medication, Adenosine or Lexiscan, which dilates the blood vessels into your heart, increasing blood flow, therefore simulating exercise for patients unable to exercise on treadmill. 
Cardiolite: Technetium Cardiac Agent is used in place of the Thallium. The resting portion of the test is done first. Your appointment will last approximately 2 ½ to 3 hours. You do not have to return in the afternoon. 
Pharmacologic Cardiolite: Same as above, except you will also be injected with a medication, Adenosine or Lexiscan, which dilates the blood vessels into your heart, increasing blood flow, therefore simulating exercise for patients unable to exercise on treadmill. 
Exercise Treadmill Test: You will be here about 1 hour.


 When will my doctor get the test results? Usually results are available within 2 to 3 days.

How much radiation will I receive?  You will be given a little more than what you would receive from a chest x-ray.

Where does the radiation go?  The injected dose is removed from the body through your body's waste.

Why is it a concern if I may be pregnant or nursing?  Depending on your condition, this kind of stress imaging may be inappropriate for you.  Discuss your condition with your doctor.  Ideally, for women of childbearing capacity, heart imaging should be performed during the first few (approximately 10) days following the onset of the menstrual period.

Can there be any adverse reactions?  Adverse reactions associated with the imaging agent are extremely rare, but can occur.  If your doctor has prescribed medication instead of exercise, you may experience some sensations such as flushing or some chest discomfort.  Contact your doctor immediately if you have any concerns regarding a possible reaction.

Is this going to HURT?  You will feel a pinprick when the IV needle is inserted into a vein.

The HEART receives blood and nutrients from blood vessels called the coronary arteries.  If these arteries become narrowed or partially blocked by the buildup of plaque, the heart cannot work at its best.  Other terms used for narrowing of the coronary arteries are coronary atherosclerosis or coronary artery disease (CAD).  When additional work is placed on the heart, it must pump faster.  To do this, the heart muscle itself requires more blood.  The pictures taken of your heart reflect the BLOOD FLOW to the heart muscle.  When increased work demand or stress on the heart occurs in the presence of coronary artery disease, the heart cannot receive the blood it needs.  This may cause chest pain or angina and may progress further to a heart attack (myocardial infarction).  Stress imaging of the heart provides information to your physician which is useful for detecting the presence and significance of coronary artery disease and the health of the heart muscle.