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Medical Video: Gated Blood Pool Scan
Definition
What is a heart blood pool scan?
The heart blood pool scan shows how well your heart is pumping blood throughout the body. During this test, a small amount of radioactive substance called a tracer will be injected into a blood vessel. A gamma camera will detect radioactive substances that flow through the heart and lungs. The percentage of blood pumped out of the heart with each heartbeat is called the ejection fraction. This gives an idea of how well the heart works.
There are two types of heart blood pool scans:
- First-pass scan. This scan produces a picture of blood when it first passes through the heart and lungs. First-pass scans can be used in children to see problems in the heart that have existed since birth (congenital heart disease).
Gated scan or multigated acquisition (MUGA) scan. This scan uses an electrical signal to trigger the camera to take several pictures that can later be seen as moving images. The image records the movement of the heart and determines whether the heart is pumping properly. An MUGA scan can take 2 to 3 hours to collect everything you need to see and can do before or after you exercise. You may be given nitroglycerin to see your heart's response to this drug. MUGA scan can be done after the first-pass scan. This scan is not usually done in children.
When should I undergo a heart blood pool scan?
A heart blood pool scan is performed for:
- check the size of the heart chamber (ventricles)
- check the work of the heart pump in the lower ventricle
- look for if there are abnormalities in the ventricular wall such as aneurism
- looking for abnormalities in blood movement between the heart chambers.
Prevention & warning
What should I know before undergoing a heart blood pool scan?
Imaging of the heart's blood pool is usually not done during pregnancy because the radiation beam can damage fetal development. MUGA scans are routinely used before and after receiving a heart transplant to assess how well the heart works. MUGA is also used to monitor ejection fraction in those who receive chemotherapy. In general, echocardiograms provide information as much as MUGA scans and are less invasive. However, MUGA scans provide more accurate information regarding ejection fraction than echocardiogram, especially for people with obesity or lung disease.
Process
What should I do before undergoing a heart blood pool scan?
Before scanning the heart blood pool, notify the medical person if you:
- allergic to a drug
- moderate or possible pregnancy
- recently did a radioactive tracer test, such as a bone or thyroid scan
- have a pacemaker or other metal device in your chest. This device can complicate the acquisition of images of blood flow through the heart clearly
You may be asked not to eat and drink for several hours before the examination. You should not consume caffeine or smoke for 4 to 6 hours before the examination. If the examination includes sports, you should wear comfortable clothes and shoes. Many drugs can affect the results of this test. Be sure to tell your doctor all the prescription and nonprescription medicines you are using.
You will be asked to release jewelry that can interfere with the scan process. You may need to remove all or part of your clothes. You will be given special clothes during the examination.
How is the heart blood pool scan?
You will lie on the examination table under the monitoring of a gamma camera. An electrocardiogram (ECG, ECG) electrode will be attached to your chest so that your heart's electrical signal can be detected as well. Then the camera, which is a round metal instrument about 3 ft (1 m) wide, will be positioned close to your body. If you feel cold or uncomfortable lying on the table, ask the technician for a pillow or blanket. The camera will be positioned in a different place on your chest to record different images of your heart.
The technician will clean the part of your arm that will be injected with radioactive tracer. An elastic tie, or tourniquet, is then wrapped around your upper arm to temporarily stop the blood flow in your arm. This makes it easy to inject a syringe into a vein correctly. A small amount of radioactive tracer is then injected, usually into a vein inside your elbow.
If you do an MUGA scan, a blood sample will be taken and a tracer will be added to the sample, then it will be injected back into your veins.
Gamma cameras will take pictures when a radioactive tracer moves through the bloodstream and into your heart. It is important not to move during the scan.
The camera does not produce any radiation, so you are not exposed to radiation when the scan is complete. You need to remain silent during each shot, which can take up to 5 minutes. You may be asked to:
- change position for each picture differently
- do some light exercise between the scans to see how well your heart is functioning after the stress of exercising
- use nitroglycerin to see the heart's response to this drug
The radioactive tracer is designed to attach to your blood cells, which takes 20 to 30 minutes. You will then wait 2 to 4 hours for the tracer to be completely absorbed by your red blood cells. During this time, you may remain at the test center. Some test centers allow you to go and come back when your test arrives. The test usually takes 10 minutes to 1 hour, depending on the research conducted. The MU scan requires 2 to 3 hours to collect all the required images.
What should I do after undergoing a heart blood pool scan?
When your scan is done, you can usually leave the test room immediately. You may wait at the test center until all your scanned images have been reviewed. If you move during the scan and the resulting image is not clearly visible, the scan process may need to be repeated.
Drink plenty of mineral water and urinate frequently after the scan is complete to make sure the tracer is completely out of the body. It took one to two days for the tracer to completely disappear.
If you have questions relating to the process of this test, consult your doctor for a better understanding.
Explanation of Test Results
What do the test results mean?
The most commonly reported value is the ejection fraction, which is the average amount of blood pumped out of the left ventricle of the heart during each contraction. Normal results are:
- ejection fraction is 55% to 60%
- ventricular walls contract normally
Many conditions can affect the results of a heart blood pool scan. The doctor will discuss with you if there are abnormal results related to your symptoms and medical history.
Hello Health Group does not provide medical advice, diagnosis or treatment.
