Nuclear Exercise Stress Test
What a nuclear exercise stress test is
Sometimes, the arteries that supply blood to the heart muscle can become clogged or narrowed from the buildup of plaque. This is called atherosclerosis or coronary artery disease. A nuclear exercise stress test evaluates blood flow to your heart muscle — during periods of exercise (stress) and rest — to help doctors determine if you have a blockage in one or more arteries of the heart.
For this procedure, we use safe, radioactive tracers that are injected into your blood through an IV (intravenous) line — via a vein in your arm — to examine your blood flow. Images of the tracers allow us to see the heart muscle receiving the blood supply more clearly.
A nuclear exercise stress test has three parts: imaging while you are at rest, monitoring your heart while you exercise and imaging after you exercise.
To begin, you will be taken to an exam room where our nuclear medicine technologist will explain the procedure and answer any questions. We will then place an intravenous (IV) line in your arm, and our technologist will inject the first radioactive tracer into the IV line. The radioactive tracer will need to circulate through your blood for a while before scanning can begin.
During the first imaging session, you will lie flat on your back on a table with your left arm resting above your head. Cameras will slowly move around your chest for about 20 minutes. It is very important for you to lie as still as possible during the imaging session. You can breathe normally during this part of the test.
Next, you will be taken to the treadmill room for the exercise portion of the test. Our medical assistant will gather your medical history, explain the test and answer any questions. At that time, you will need to sign a consent form.
The technician will then use gel to place small plastic pads on your chest that connect to an electrocardiogram (EKG) monitor to measure the electrical signals from your heart. For men, we may need to shave small areas to remove chest hair to ensure the pads stick. We also will take a baseline blood pressure reading at this time.
When the nurse arrives, you will begin walking on the treadmill at a slow pace. During this time, if you develop any discomfort, please tell the nurse immediately. If you feel the need to stop while walking, tell the nurse so that a second radioactive tracer can be added to your IV line. You will resume walking on the treadmill for one to two minutes after getting the second tracer.
After the exercise portion of the test, we will remove the EKG pads and IV line. You will then have a break before a second imaging test. During this waiting period, you may have a small low-fat meal, regular coffee (no cream) and any other liquids.
After the break, you will have another 20-minute imaging session, following the same steps as the first one. The complete nuclear exercise stress test process will take about four hours.
You will have short breaks between portions of the test.
You may resume your regular diet and routine after the last imaging session. We will send a copy of the report to your referring doctor.
- Ask your doctor if you need to stop taking your medications, such as beta-blockers, before the test.
- Avoid all food and drink for four hours before your appointment. If you eat or drink, you will need to reschedule your test.
- Avoid caffeine, caffeinated beverages or chocolate for 24 hours before your appointment. This includes coffee, tea, cocoa, soda and other caffeinated drinks.
- Bring or wear loose, comfortable clothing and shoes suitable for brisk walking or jogging. Avoid heels or sandals. Avoid wearing a dress, full slip or tight jeans. Wear pants or shorts and a loose-fitting top.
- Bring a list of your current medications or bring the medications in their bottles.
- Take any medications with sips of water unless otherwise instructed by your doctor.
- Talk to your doctor and reschedule your test if you are pregnant, may be pregnant or are a nursing mother.
Navigate Your Health


Find a Heart & Vascular Physician
Find a Heart & Vascular Physician
Meet our doctors who specialize in the full range of heart and vascular care. Our team of experts has experience in a variety of specialty areas. Together, we provide comprehensive evaluation, diagnosis and treatment options.
Find a Doctor

Patient Portal
Patient Portal
If you are a patient at Orlando Health Heart & Vascular Institute, our free online patient portal provides an easy and secure way to manage your health information. Reach us from any location at a time that’s convenient for you.
Learn More

Virtual Visit
Virtual Visit
Need to talk with a doctor, but don’t want to leave your home? Try our virtual visit (telehealth) option to connect with a physician from your phone, tablet or computer.
Learn More