What is a nuclear cardiology stress test?

This noninvasive test assesses blood-flow patterns to the muscle of the heart to determine whether coronary artery disease is the cause of your symptoms. The test also evaluates the progression of the disease in patients already diagnosed with coronary artery disease.

Coronary artery disease produces stenosis, narrowing and potentially blockages in the arteries that supply blood to the muscle of the heart. Performing the nuclear stress test will provide your physician with information on the impact the disease has had on blood flow to the heart during exercise or stress.

Are there any special instructions I need to follow prior to the test?

When you schedule your test, we’ll review all of your medications (be sure to bring your complete medication list). We may ask that you not take certain medications prior to the test.

It’s important that you not consume any caffeine for a full 24-hour period prior to your appointment. This includes coffee, decaffeinated coffee, tea, soda, chocolate, and certain migraine medications that contain caffeine. Caffeine can inhibit the medication needed for the stress portion of the test to be effective. If you’ve consumed caffeine within 24 hours, we may have to reschedule your test.

What happens during the stress portion of the test?

We begin the test by obtaining a brief medical history, starting an intravenous line, and placing leads on your chest to monitor your heart. Patients who exercise will have their heart rate and rhythm, blood pressure, and any symptoms monitored closely by the nurse clinician. When you reach an acceptable level of exercise, the radioactive dose will be injected into your intravenous line. You will need to exercise for a final minute to allow it to reach your heart. Immediately after exercise, you will be taken to the nuclear camera room.

What if I am unable to exercise?

Patients who cannot exercise are given medication that affects the heart the same way that exercise does.

What happens during the stress-imaging portion of the exam?

You will be asked to lie on your back, knees flexed and supported, and raise your arms over your head so that the camera can be positioned directly above your heart. For longer images, EKG leads will be placed on your chest to allow the imaging equipment to be synchronized with your heartbeat. This is called a "gated" nuclear cardiology test. Once the leads are in place, the camera will be set up to take a series of images of your heart as it moves around your body.

How is the exam interpreted?

If the radioactive isotope that you were given is evenly distributed, that indicates adequate blood flow. It it’s not, that means your blood flow is restricted by defects. Matching these defects during stress and rest show the areas of the heart that have been affected by a heart attack or myocardial infarction. Areas that have defects during stress but don’t show up during rest signify ischemia, or impaired blood flow. Images from this test also tell the cardiologist how your heart contracts.

What happens after the examination?

After a nuclear cardiologist specializing in nuclear imaging interprets your test, he’ll give the results to your cardiologist who will then contact you and explain the results. It may take up to 72 hours before you are notified. The results from both the stress and rest portions of the test help to formulate a treatment plan to meet your specific needs.