What is a nuclear stress test?
A nuclear stress test, also called myocardial perfusion imaging (MPI) study, cardiac PET study, cardiac SPECT study or cardiac stress test, gives you a clearer understanding of how your heart functions under different levels of activity. It evaluates blood flow to the heart muscle using a radioactive substance moving through your arteries and is commonly used to assess which parts of your heart are working properly and which are not. It can be used to detect coronary artery disease or other heart conditions.
Who would need a nuclear stress test?
Your doctor might recommend a nuclear stress test if you’re experiencing symptoms such as shortness of breath or chest pain. It could also be recommended if a regular exercise stress test doesn’t provide conclusive results. If you’ve suffered a heart attack, a nuclear stress test can help your doctor determine the damage done to your heart. If you have already been diagnosed with coronary artery disease, a nuclear stress test can help your doctor better understand your risk of a heart attack or other event and determine a treatment plan and/or further interventions such as angioplasty or bypass surgery.
What are the risks of a nuclear stress test?
There are inherent risks with any medical procedure and a nuclear stress test is no different. Because there is radiation and stress to your heart involved, there are some minor risks but the procedure is generally considered safe. You may experience an allergic reaction to the radioactive tracer or any medications used during the test. There is also risks with radiation exposure although low; pregnant women should avoid nuclear stress tests due to potential damage to the fetus from radiation exposure. You could experience a drop in blood pressure before or after exercising, which may result in fainting. Although extremely rare, arrythmia or a heart attack may be induced by the stress portion of the test – but it’s important to remember you will be under the close supervision of your healthcare team. You should always discuss any concerns or potential risks with your healthcare provider prior to your procedure. They are in the best position to advise you based on their knowledge of your personal health history.
How do I prepare for a nuclear stress test?
Prior to your nuclear stress test, your healthcare provider will provide you with instructions on how to prepare. Generally speaking, they will advise on any medications that you may need to discontinue temporarily so as to not interfere with the accuracy of the test – you should never stop taking a medication without the instruction of your provider. You should fast (depending on time of test), and avoid drinking liquids other than water. You may not have caffeine for 24 hours prior to your test. Do not smoke or drink alcohol or caffeine prior to your test.
The day of your test, you should plan to wear comfortable clothing and shoes that will allow you to walk on a treadmill. Bathe before your test and avoid wearing any lotions, oils or perfumes. If you’re unable to exercise, you should discuss your concerns with your provider as there are some medications that can be given to induce stress.
What to expect during a nuclear stress test?
Upon arriving, your healthcare team will prepare you for the test. They will place electrodes on your chest and perhaps your legs and arms, then put a blood pressure cuff on your arm. Next, they will place an IV in your arm and administer the a small amount of radioactive substance often called a tracer or radioactive tracer through an IV. The tracer may feel cold at first. You will be asked to lie on a table as your healthcare provider begins taking images of your heart at rest.
A special camera (known as a gamma camera) creates pictures of your heart and blood flow, while the electrodes placed on your chest monitor your EKG. Then you will be asked to walk on a treadmill, increasing the pace steadily until you’ve reached your target heart rate. You will be given more radioactive tracer and a second set of images will be taken. Through these images, your healthcare provider is able to determine which areas of your heart aren’t receiving proper blood flow.
You should plan for the test to take 3 ½ hours to 4 hours as multiple sets of images will be obtained.
What happens after a nuclear stress test?
When the test is complete, you may be asked to lie down while your provider monitors your heartbeat. You should be able to resume normal activities under the guidance of your healthcare provider. You do not need to do anything to rid your body of the radioactive tracer except drink plenty of water. Your body will naturally expel it through urination.