Cardiac Blood Pool Scan
Allergic reactions to the radioactive tracer are rare. Most of the tracer will be eliminated from your body (through your urine or stool) within a day, so be sure to promptly flush the toilet and thoroughly wash your hands with soap and water. The amount of radiation is so small that it is not a risk for the people you come in contact with after the test.
Occasionally, some soreness or swelling may develop at the injection site. These symptoms can usually be relieved by applying moist, warm compresses to your arm.
There is always a slight risk of damage to cells or tissue from being exposed to any radiation, including the low level of radiation released by the radioactive tracer used for this test.
A cardiac blood pool scan shows how well your heart is pumping blood to the rest of your body.
The most commonly reported value is the ejection fraction, which is the average amount of blood pumped out of the heart's left ventricle during each contraction.
Normal results include:1
- Ejection fraction is 55% to 65%.
- Walls of the ventricles are contracting normally.
Many conditions can affect cardiac blood pool scan results. Your doctor will discuss any significant abnormal results with you in relation to your symptoms and past health.
What Affects the Test
Reasons you may not be able to have the test or why the results may not be helpful include:
- Fast or irregular heart rhythms.
- Long-acting nitrate medicines and digoxin.
- Recent nuclear scans, such as thyroid or bone scans.
- Barium, such as from a barium enema, and bismuth, such as Pepto-Bismol.
- Inability to remain still during the test. You may not be able to have the test if you have severe back problems or other physical disabilities that prevent you from lying flat.
What To Think About
- Cardiac blood pool imaging is not usually done during pregnancy because the radiation could damage a developing fetus.
- The cardiac blood pool scan is a safe and accurate way to determine overall heart function.
- Multigated acquisition (MUGA) scans are routinely used before and after receiving a heart transplant to assess how well the heart is working. MUGA also may be used to monitor the ejection fraction in people receiving chemotherapy.
- Generally, an echocardiogram provides as much information as a MUGA scan and is less invasive. But a MUGA scan provides more accurate information about ejection fraction than an echocardiogram, especially in people who are obese or who have lung disease. To learn more, see the topic Echocardiogram.