Nuclear Cardiology

Contents:

• What is a Nuclear Stress Test?
• Examples of possible nuclear stress test results
• Who will read my Nuclear Stress Test?
• Preparation for Nuclear Stress Testing
• More information on Cardiac Nuclear Imaging
              (page will open in new browser)

*May also be referred to as "Cardiolyte" or "Thallium" or "Adenosine" Test

By producing an image of the heart,  radioactive "tracers"  such as Thallium and Cardiolyte can increase the accuracy of a traditional stress test.  Nuclear scanning of the heart shows how well blood flows to the heart muscle. It's usually done in conjunction with an exercise stress test on a treadmill, but can also be performed using medicines such as adenosine and dipyridamole that effectively simulate the effects of exercise on the heart.   Cardiac Nuclear Stress Imaging helps determine whether coronary artery stenoses (blockages) are so severe as to limit blood flow to heart muscle when it needs it most… during physical activity.   In addition, nuclear imaging allows a determination of the heart’s pumping function (ejection fraction). 

When a patient reaches his or her maximum level of exercise, or after simulating exercise with medications, a small amount of tracer is injected into a vein. The patient then lies down on a table under a camera that detects the energy emitted from the radioactive tracer and generates pictures (or scans) that reflect the heart’s blood flow both at rest and following stress. If a portion of the heart muscle is under-perfused (doesn't receive a normal blood supply), a deficiency of tracer activity in that area will appear on the finished images as a “defect".

At the Heart Care Centers of Illinois offices, resting pictures are first obtained using a Thallium agent.  Next, stress is performed using treadmill exercise or medications (adenosine stress test).  At the peak of exercise, Cardiolyte is injected into the bloodstream to determine the heart’s blood flow during activity.  Our “tracers” and methods are both widely used and quite safe.  The amount of radiation you will receive is comparable to that from an X-ray.  Cardiologists, nurses and technologists with expertise in nuclear cardiology supervise and analyze these tests.

Back to Top

• If the scan is normal during both exercise and rest, then blood flow through the coronary arteries is most likely normal as well. No significant coronary artery blockage is suspected.

• If the scan is normal at rest but abnormal following exercise (a reversible perfusion defect), then the heart isn't receiving enough blood when it's under stress. This may be due to blockage in one or multiple coronary arteries.   See examples of Reversible Perfusion Defects... CASES.

• If abnormal blood flow is detected both at rest and with stress, this suggests that part of the heart has suffered injury in the past.  This is often the case following a heart attack.

Back to Top

Who will read my Nuclear Stress Test?

Heart Care Centers features four cardiologists who are Board Certified in Nuclear Cardiology. These doctors interpret the results from your nuclear stress testing. A preliminary report is issued the same day of the test, with a printed and final version faxed to your primary physician within 24 hours.

Back to Top

Preparation for Nuclear Stress Testing

Click here to print instructions on preparation for stress testing


     Suggestions to make your nuclear stress test more accurate and comfortable.

• No solid food for four hours before the test.  No nicotine on the day of the test. Fluid intake is fine. 

• Wear comfortable clothing and shoes

• No Beta-Blockers the morning of the test (unless your physician specifies otherwise).  Beta-Blockers include:   Blocadren, Corgard, Inderal (propranolol), Lopressor and Toprol (metoprolol), Normodyne & Trandate (labetolol), Sectral, Tenormin (atenolol), Visken (pindolol), and Ziac.

• Take all other medications.   

• Allow two to three hours for the exam.

• Some nuclear tests are scheduled over two days, requiring approximately one and one-half hours per day.  This is necessary in order to provide high quality images for some patients.

For Nuclear testing with Adenosine Stress:

Important:  No Caffeine, coffee or caffeinated beverages for 12-24 hours prior to the test (this includes colas, tea, chocolate products, and even decaffeinated coffee).  No Theophylline medications (including Theo-Dur, aminophylline, etc.) for 24-48 hours before the test.

Back to Top