A cardiac perfusion scan measures the amount of blood in your heart
muscle at rest and during exercise. It is often done to find out what may be
causing symptoms like angina (such as chest pain or pressure). It may be done after a
heart attack to see if areas of the heart are not
getting enough blood or to find out how much heart muscle has been damaged from
the heart attack.
During the scan, a camera takes pictures of the heart after a
special test medicine (radioactive tracer) is given through an IV. The tracer travels through the blood and into the heart
muscle. As the tracer moves through the heart muscle, areas that have good
blood flow absorb the tracer. Areas that do not absorb tracer may not be
getting enough blood or may have been damaged by a heart attack.
An enlarged heart (cardiomegaly) may have various causes. But it's usually the result of high blood pressure (hypertension) or coronary artery disease.
An enlarged heart may not pump blood effectively, resulting in congestive heart failure. Cardiomegaly may improve over time. But most people with an enlarged heart need lifelong treatment with medications.
Two sets of pictures may be made during a cardiac perfusion scan.
One set is taken while you are resting. Another set is taken after your heart
has been stressed, either by exercise or after you have been given a medicine.
The resting pictures are then compared with the stress images.
This test is also known by other names including myocardial perfusion scan, myocardial perfusion imaging, thallium scan, sestamibi cardiac scan, and nuclear stress test.
Why It Is Done
A cardiac perfusion scan is done to:
Find the cause of unexplained chest pain or pressure.
Find the cause of chest pain or pressure brought on by exercise.
Check for the location and
amount of damage caused by a heart attack.
treatment decisions for a person with CAD.
Check to see that the heart is getting enough blood after heart
surgery or angioplasty.
congenital heart defect and determine how serious it
is. These scans may also be done following surgery to correct a congenital
How To Prepare
Before a cardiac perfusion, tell your doctor if you:
Are taking any medicines, including
erection-enhancing medicines (such as Cialis, Levitra, or Viagra). You may need
to take nitroglycerin during this test, which can cause a serious reaction if
you have taken an erection-enhancing medicine within the previous 48 hours. Ask
your doctor whether you need to stop taking any of your other medicines before
Are allergic to any medicines or
Are or might be pregnant.
breast-feeding. The radioactive tracer used in this test can get into your breast milk. Do not breast-feed your baby for 2 days after this test. During this time, you can give your baby breast milk you stored before the test, or you can give formula. Discard the breast milk you pump for 2 days after the test.