What Is a Nuclear Ventriculography?
A nuclear ventriculography is a test that examines the chambers of your heart. The test will create images of your heart that your doctor will use to see how well it pumps. The images also allow your doctor to see the size of your heart’s chambers.
This test uses a radioactive substance that can be seen using a special type of camera. An electrocardiogram (ECG), a test that detects electrical activity in the heart, will be done at the same time so the camera can take pictures at different intervals in the heart’s cycle.
A nuclear ventriculography is also called a multigated acquisition scan (MUGA) or radionuclide ventriculography (RNV).
What Is the Purpose of the Test?
A nuclear ventriculography is ordered to see if your heart is pumping properly. The test can identify ejection fraction, which shows the strength of the heart’s contraction. A nuclear ventriculography can also be used to determine the location of a pumping problem in your heart chambers. Test results can be used to help diagnose:
- coronary artery disease
- systolic heart failure (a problem with the heart’s contractions)
- heart valve disease
- previous heart attack
Nuclear ventriculography, combined with an echocardiogram or cardiac magnetic resonance imaging (MRI), can be used to gain information about or diagnose other conditions. These conditions include:
- atrial septal defect
- dilated cardiomyopathy
- idiopathic cardiomyopathy
- peripartum cardiomyopathy
- heart failure
- senile cardiac amyloidosis
Preparing for the Test
It is necessary to avoid caffeine for 48 hours before the test. Caffeine can affect your heart and change the results. Caffeine may be found in coffee, chocolate, tea, and certain sodas.
Your doctor may also ask you to avoid drinking and eating for a few hours before the test. It is important to tell your doctor about any prescription or over-the-counter medications you are taking. Your doctor may ask you to stop taking your medication before the test or change the dosage.
Inform your doctor if you are pregnant or breastfeeding. The nuclear substance used during the test may be passed to the fetus or excreted in breast milk.
Before having the test, you will need to remove all metal from your body, including jewelry and belts. If you have a metal plate or screw in your body, inform your doctor and the technician.
What Happens During the Test
You will need to change into a hospital gown so the technican has access to your chest. The technician will ask you to lie down on an examination table. The first step of the test is to have the radioactive substance, called technetium, injected into your body.
The technician will insert an intravenous (IV) line into a vein into your arm, usually on the inside of the elbow. You may feel mild to moderate pain when the IV is inserted. The radioactive tracer will be inserted through the IV line. It is normal to feel flushed or chilled as the radioactive tracer makes its way into your body. The technician will apply electrodes to different areas on your chest for the electrocardiogram.
When the radioactive tracer has entered your bloodstream, the IV will be removed. The radioactive substance will make its way to the heart via the bloodstream. The technician will place you under a special type of camera and begin taking pictures. He or she may ask you to change positions in order to get certain images. It is important that you remain still while the pictures are being taken.
Your doctor may order an exercise stress test in conjunction with your nuclear ventriculography. This helps your doctor to see how well your heart performs during activity. You will be asked to walk or run on a treadmill until a target heart rate has been reached. When you reach this heart rate, you will move back to the examination table to have more pictures taken. When all of the images have been captured, the technician will remove the electrodes from your chest and you will be able to leave.
You should be able to return to your normal activities, including eating and drinking, after the test. It is important that you drink plenty of fluids after the test to help the radioactive substance be excreted from your body.
What Are the Risks?
Nuclear ventriculography is considered a noninvasive test with very low risk. The test exposes you to a small amount of radiation from the radioactive tracer. However, this is a lower dose of radiation than an occurs from an X-ray. It is safe to have occasional nuclear medicine tests.