Resting Radionuclide Angiogram
What is a resting radionuclide angiogram?
Resting radionuclide angiogram (RNA) is a type of nuclear medicine procedure. This means that a tiny amount of a radioactive substance, called a tracer, is used during the scan to help show the heart’s chambers in motion. This test can tell the doctor how well the heart pumps and how much blood is pumped with each heartbeat. This is called the ejection fraction.
A radioactive tracer (usually technetium) is injected into an arm vein to “tag" blood cells so they can be tracked with a scanner as they move through the heart. A special camera (called a gamma camera) then makes recordings of the heart muscle at work, like a movie. These recordings will be matched with the electrocardiogram (ECG). An ECG is a recording of the heart's electrical activity.
When the heart tissue doesn’t get enough blood, it can’t function as well as it should. Over time, the heart muscle becomes weak due to a lack of oxygen.
If the heart muscle doesn’t move normally, or not enough blood is pumped out by the heart, it may be a sign of one or more of the following:
- Injury to the heart muscle, possibly as a result of decreased blood flow to heart muscle due to clogged coronary arteries
- An enlargement of one or more of the heart's chambers
- Aneurysm (a weak area in the heart muscle)
- Toxic effects of certain medications
Why might I need a resting radionuclide angiogram?
Reasons for your doctor to request a resting radionuclide angiogram (RNA) include:
- Chest pain
- Shortness of breath
- Fatigue (extreme tiredness)
If your doctor thinks you have some type of heart disease, a resting RNA may be done.
There may be other reasons for your doctor to recommend this test.
What are the risks of a resting radionuclide angiogram?
Only a small amount of the radioactive tracer is used. So, there is no need for precautions against radiation exposure.
The injection of the radioactive tracer may cause some sight discomfort. Allergic reactions to the tracer are rare.
If you are pregnant or think you may be, tell your healthcare provider. Radiation exposure during pregnancy may lead to birth defects. If you are breastfeeding, tell your healthcare provider.
There may be other risks depending on your specific medical condition. Be sure to discuss any concerns with your doctor prior to the procedure.
Certain factors may interfere with or affect the results of this test. These include:
- Caffeine intake before the procedure
- Smoking or using any form of tobacco before the procedure
- Certain heart medications
How do I prepare for a resting radionuclide angiogram?
- Your doctor will explain the procedure to you and ask if you have questions.
- You will be asked to sign a consent form that gives your permission to do the test. Read the form carefully and ask questions if anything is not clear.
- Generally, no sedation is needed. You may be told to fast (not eat or drink) for at least 3 to 4 hours before the study.
- Tobacco use and caffeine intake may also be restricted 2 or 3 hours before testing.
- If you are pregnant or think you may be, tell your doctor. Radiation exposure during pregnancy may lead to birth defects.
- If you are breastfeeding, tell your healthcare provider. There is a risk of contaminating breast milk with the radioactive tracer.
- Tell your doctor of all medications (prescription and over-the-counter), vitamins, herbs, and supplements that you are taking.
- Tell the technologist or doctor if you are allergic to or sensitive to medications, local anesthesia, contrast dyes, iodine, or latex.
- Tell your doctor if you have a pacemaker.
- Based on your medical condition, your doctor may request other specific preparation.
What happens during a resting radionuclide angioram?
A resting radionuclide angiogram (RNA) may be done on an outpatient basis or as part of your stay in a hospital. Procedures may vary depending on your condition and your doctor's practices.
Generally, a resting RNA follows this process:
- You will be asked to remove any jewelry or other objects that may interfere with the procedure.
- If you are asked to remove your clothing, you will be given a gown to wear.
- An intravenous (IV) line will be started in your hand or arm.
- You will be connected to an ECG machine with leads that stick to your skin and a blood pressure cuff will be placed on your arm.
- You will lie flat on a table in the procedure room.
- The radioactive tracer will be injected into the IV to “tag" the red blood cells. You will probably not feel anything when the tracer is given.
- As another option, a small amount of blood may be withdrawn from your vein so that it can be tagged with the tracer. The tracer will be added to the blood and will be absorbed into the red blood cells, then the blood will be returned into your vein through the IV.
- During the procedure, it will be very important for you to lie as still as possible, as any movement can affect the quality of the scan.
- The gamma camera will be positioned over you as you lie on the table. It will record images of your heart as it pumps the tagged blood cells through your body.
- You may be asked to change positions during the test; however, once you have changed position, you will need to lie still without talking.
- After the scan is done, the IV line will be removed, and you will be allowed to leave, unless your doctor instructs you differently.
What happens after a resting radionuclide angiogram?
Be sure to move slowly when getting up from the scanner table to avoid any dizziness or lightheadedness from lying flat for the length of the procedure.
You will be instructed to drink plenty of fluids and empty your bladder frequently for 24 to 48 hours after the test to help flush the remaining radioactive tracer from your body.
The IV site will be checked for any signs of redness or swelling. If you notice any pain, redness, and/or swelling at the IV site after you go home, you should notify your doctor as this may be a sign of infection or other type of reaction.
Your doctor may give you other instructions after the procedure, depending on your particular situation.
Before you agree to the test or the procedure make sure you know:
- The name of the test or procedure
- The reason you are having the test or procedure
- The risks and benefits of the test or procedure
- When and where you are to have the test or procedure and who will do it
- When and how will you get the results
- How much will you have to pay for the test or procedure
- Bass, Pat F. III, MD, MPH
- newMentor board-certified, academically affiliated clinician