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.
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.
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
This test is also known by other names including myocardial perfusion
scan, myocardial perfusion imaging, thallium scan, sestamibi cardiac scan, and nuclear
Why It Is Done
A cardiac perfusion scan is done to:
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.
make treatment decisions for a person with CAD.
Check to see that the heart
is getting enough blood after heart surgery or angioplasty.
Identify a congenital heart defect and determine how serious
it is. These scans may also be done following surgery to correct a congenital heart
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 the test.
Are allergic to any medicines or
Are or might be pregnant.
Are breastfeeding. The radioactive
tracer used in this test can get into your breast milk. Do not breastfeed 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.
Do not eat or drink for at least 3 hours before
a cardiac perfusion scan. If you are having a stress scan, avoid alcohol, tobacco,
caffeinated beverages, and nonprescription medicines for at least 24 hours before
Wear comfortable shoes and loose shorts or pants suitable for exercise.
Remove all jewelry before the test.
Talk to your doctor about any concerns you
have regarding the need for the test, its risks, how it will be done, or what the
results may mean. To help you understand the importance of this test, fill out the
medical test information form(What is a
It Is Done
A cardiac perfusion scan is usually done in a hospital radiology
or nuclear medicine department, a doctor's office, or at an outpatient clinic. The
test is done by a doctor and technologist trained in nuclear medicine.
For resting scans, in which you do not exercise, you will be
asked to remove your clothing above the waist, and you will be given a hospital gown
to wear. Electrodes might be attached to your chest to keep track of your heartbeats.
will have a very thin tube, called an IV, going into your arm or hand. A small amount
of the radioactive tracer will be put in the IV.
You will lie on your back on
a table with a large camera positioned above your chest. The camera records the tracer's
signals as it moves through your blood. The camera does not produce any radiation,
so you are not exposed to any additional radiation while the scan is being done.
will be asked to remain very still during each scan, which takes 5 to 10 minutes.
The camera will move to take more pictures at different angles. Several scans will
The entire test takes 30 to 40 minutes, after which you can resume
your normal activities.
Stress scan using medicine
stress scan is done in two parts. In many hospitals, the first images are taken while
the person is at rest. Then a second set of images is taken after the person is given
a medicine such as adenosine, which makes the heart respond like it would to exercise.
Sometimes the stress scan is done first and the resting scan might be done the next
A stress test with medicine is usually used when a person cannot exercise
for some reason.
For this test, you will be asked to sit or lie on the examining
table and you will be given a routine electrocardiogram (EKG or ECG), which takes
about 5 to 10 minutes.
Then you will be given the medicine through your IV.
You may get a headache and feel dizzy, flushed, and nauseated from the medicine, but
these symptoms usually do not last long. Additional EKGs and blood pressure measurements
are often taken. After the medicine takes effect (about 4 minutes), a small amount
of radioactive tracer is given through your IV.
You will wait about 30 to 60
minutes. You might be asked to eat or drink something. Then you will lie down on a
table for a set of scans. The camera records the tracer's signals as it moves through
your blood. The camera does not produce any radiation, so you are not exposed to any
more radiation while the scan is being done.
Sometimes more pictures are taken
after you rest for 2 to 4 hours. Most people can resume their normal diet and activities
after the final set of scans.
Stress scan using
For stress scans using exercise, your heart rate will be checked with
an electrocardiogram (EKG or ECG). Because EKG
electrodes need to be attached to the chest to check the heart, men are usually bare-chested
and women usually wear a bra, gown, or loose shirt. To learn more, see the topic Electrocardiogram.
The exercise stress scan is done in two parts. First
a set of resting images is taken, then a set of stress images is taken immediately
after exercise. Sometimes the stress scan is done first and the resting scan might
be done the next day.
In many hospitals, first resting pictures are taken using
one type of tracer. More pictures are taken using a different tracer after your heart
has been stressed by exercise.
In this stress test, you exercise on a treadmill
or stationary bike. Your heart rate will be checked during the test with standard
electrocardiography. Your blood pressure is checked using a blood pressure cuff placed
on your arm. To learn more, see the topic Exercise Electrocardiogram.
You will begin by walking or pedaling slowly
and easily. Every few minutes, the speed or incline of the treadmill or resistance
of the bike may be increased. You will exercise until you need to stop or until you
reach a suitable heart rate. At that point, you will be given a different tracer medicine
through your IV.
You will then lie down on a table for scanning. Each scan takes
5 to 10 minutes. The camera does not produce any radiation, so you are not exposed
to any additional radiation while the scan is being done.
Sometimes more pictures
are taken after you rest for 30 minutes to 4 hours. In some hospitals, you are given
more radioactive tracer several hours after exercise and before the final image.
people can resume their normal diet and activities after the final set of scans.
plenty of fluids for the next 24 hours to help flush the tracer out of your body.
If you have kidney, heart, or liver disease and have to limit fluids, talk with your
doctor before you increase the amount of fluids you drink.
How It Feels
cardiac scanning test itself is painless.
You may feel a brief stinging
or burning sensation when the IV is inserted into your vein.
You may be uncomfortable
lying still for an extended period of time on the table during the scans.
medicine to stress your heart is used, you may have symptoms of mild nausea, headache,
dizziness, flushing, or chest pain. These symptoms only last a few minutes.
you are asked to exercise, you may have chest pain, breathlessness, lightheadedness,
aching in your leg muscles, and fatigue. Report these to the technician. If the symptoms
are severe, the exercise part of the test may be stopped.
You will be asked
to remain very still during each scan, which takes about 5 to 10 minutes. The camera
will move to take more pictures at different angles. Several scans will be taken.
perfusion scans are usually safe. There is always a slight chance of damage to cells
or tissue from radiation, including the low levels of radiation used for this test.
But the chance of damage from the radiation is usually very low compared with the
benefits of the test.
The risk of exercise depends on the condition of your
heart and your general level of health. The risks include:
An irregular heartbeat.
Heart attack. There is a slight risk
that death may result if a heart attack occurs during the test.
After the test
Call 911 or other
emergency services immediately if you develop:
Chest pain or pressure.
Test results are usually available within 1
to 3 days.
A cardiac perfusion scan measures the amount of blood in your heart
muscle at rest and during exercise.
if radioactive tracer is evenly distributed throughout your heart muscle.
if areas of abnormal tracer absorption are present. This means some areas of heart
muscle are not getting enough blood (ischemia). This may mean that the heart has been
damaged or that coronary artery disease is present.
Reasons you may not be able to have the test or why the results may
not be helpful include:
Dunning MB III (2015). A Manual of Laboratory and Diagnostic Tests, 9th ed.
Philadelphia: Wolters Kluwer Health.
Chernecky CC, Berger BJ (2013). Laboratory Tests and Diagnostic
Procedures, 6th ed. St. Louis: Saunders.
Fischbach F, Dunning MB III (2015).
A Manual of Laboratory and Diagnostic Tests, 9th ed. Philadelphia: Wolters Kluwer
Klocke FJ, et al. (2003). ACC/AHA/ASNC guidelines for the clinical
use of cardiac radionuclide imaging-Executive summary. A report of the American College
of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation,
108(11): 1404-1418. Available online: http://circ.ahajournals.org/content/vol108/issue11/index.shtml.
ByHealthwise Staff Primary Medical ReviewerRakesh
K. Pai, MD - Cardiology, Electrophysiology E. Gregory
Thompson, MD - Internal Medicine Martin J. Gabica,
MD - Family Medicine Adam Husney, MD - Family
Medicine George J. Philippides, MD, FACC - Cardiology
Fischbach F, Dunning
MB III (2015). A Manual of Laboratory and Diagnostic Tests, 9th ed. Philadelphia:
Wolters Kluwer Health.
This information does not replace the advice of a doctor.
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