Nuclear Stress Test

A nuclear stress test is a common test that doctors use to diagnose coronary artery disease or to determine if there is a lack of blood flow to your heart as it relates to previously known blockages. A nuclear “tracer” is injected in the bloodstream. It travels through the area being examined and gives off energy in the form of gamma rays which are detected by a special camera and a computer to create images of the inside of your body.

Two sets of images are taken of your heart with a special “Gamma camera”. One set of images are a “Rest Phase” and the other is the “Stress Phase”.  A comparison is made between the two sets which determines whether or not you have significant blockages in the heart arteries.  These blockages could affect the blood flow to the heart.

Nuclear medicine imaging provides unique information that often cannot be obtained using other imaging procedures.

The team at San Tan Cardiovascular use this technology as another way to provide exceptional treatment to patients by offering this service at the Mesa office location in a convenient, professional and comfortable setting.

What are some common reasons my doctor would order this test?

  • Unexplained chest pain
  • Chest pain brought on by exercise (called Angina)
  • Shortness of breath with exertion
  • Abnormal electrocardiogram (ECG/EKG)
  • To determine the extent of injury to the heart following a heart attack
  • To evaluate the presence and extent of suspected or known coronary artery disease

Nuclear Stress Test at San Tan Cardiovascular Center

The day of the test the staff will discuss the test, have you sign a consent form, and record your height and weight.  Staff will start an IV and administer an injection of the radioisotope (nuclear medicine).  It is not a dye and will not make you feel differently. 

There will be a waiting period of approximately 45 minutes for the tracer to do its job then a set of images is taken. You will either sit up or lie down on a table where a special  “Gamma camera” will take a scan your heart for approximately 15-30 minutes.  You must remain very still during these images or it will have to be repeated. This is considered the “Resting Phase” of the test.

You will be connected to an EKG machine and your blood pressure and pulse will be checked.

For the “stress phase”, you will walk on a treadmill, with the speed and slope increased every few minutes.  The staff will look for changes in the EKG and blood pressure levels, which may tell doctors that your heart is not getting enough oxygen. Tell the staff if you experience chest pain or unusual shortness of breath while you are walking.

Once your “target heart rate” is achieved, a second dose of the nuclear tracer will be injected.  You will need to walk at least one minute following the injection to let it circulate in your bloodstream before stopping.

**If your doctor would rather you not exercise, a medication (“chemical”) can be administered into your IV to increase your heart rate for the stress phase.  It may be best to do a chemical stress test as opposed to exercise if you are not able to walk safely on the treadmill, have certain EKG patterns, a pacemaker, or a defibrillator.  In addition, if you try the treadmill and cannot achieve the target heart rate, then a chemical stress test will be necessary. 

There will be another 45 minute waiting period for the tracer to do its job. At this point, you may eat the snack you brought.

You will be scanned a second time under the gamma camera. The Physician will compare these “stress” pictures with the first set of “resting” pictures.

How do I get started?

Contact San Tan Cardiovascular Center today to make an appointment with one of our healthcare providers.

At this appointment:

  • we will review your medical history, discuss your symptoms and perform a non-invasive, diagnostic test to further determine your medical condition,
  • any pertinent testing that needs to be done beforehand will also be ordered at this time.

Our billing department will then contact your health insurance company to obtain prior authorization.  Upon receiving insurance authorization, the test will be scheduled.

Nuclear Stress Test FAQs

Q:  How should I prepare for my test?

A:  Plan to be at the office 3-5 hours.

  • NO CAFFEINE for 2 hours prior to your test. This includes ALL coffee, tea & cola products (even decaf and caffeine free), as well as all chocolate products. This could cause inaccurate test results.
  • Do not eat 4 hours prior to your test.
  • Drink lots of water the day before and the day of your test.
  • Do NOT stop any medications, unless directed by the office.
  • If you take any medications containing Theophylline (for Asthma, COPD), please stop for 48 hours prior to your test. These include: Theo-24, Theo-dur, Theoclear, Lixophylline, Primatene, Quibron, Theolair, Theo-Organidin, Slo-bid, Theo-Sav, Slo-phyllin, Theostat, TheoX, Trental, Pentoxyphilline.
  • You may bring a snack to eat after the stress portion of the test is completed.
  • Wear a 2 piece outfit. (No dresses). Do not wear shirts with metal decorations or metal snaps. This will interfere with the imaging.
  • If you are scheduled to walk on a treadmill, wear tennis shoes. For your safety, sandals, boots or bare feet will not be allowed on the treadmill.
  • Do not apply oils, lotions or powders to your skin on the day of your test. Deodorant is allowed.

Q:  When will I find out the results of the test?

A:  You will be given a separate appointment, for 1-2 weeks later, to discuss your test results with the provider.

Your results could show:

  • Normal blood flow during exercise and rest. You may not need further tests.
  • Normal blood flow during rest, but not during exercise. Part of your heart isn’t receiving enough blood when you’re exerting yourself. This might mean that you have one or more blocked arteries (coronary artery disease).
  • Low blood flow during rest and exercise. Part of your heart isn’t getting enough blood at all times, which could be due to severe coronary artery disease or a previous heart attack.
  • Lack of radioactive dye in parts of your heart. Areas of your heart that don’t show the radioactive dye have tissue damage from a heart attack.

If you don’t have enough blood flow through your heart, you may need to undergo a Coronary Angiogram. This test looks directly at the blood vessels supplying your heart.

***If you are planning on flying/traveling in the next 48 hours, please let us know***

The nuclear tracer can sometimes set off the radiation alarms. We will give you a letter indicating you had the procedure. The nuclear tracer will be completely out of your system within 60 hours.