Cardiac Nuclear Imaging (Nuclear Stress
Cardiac nuclear imaging measures the
flow of blood in your heart at rest and then during exercise. The test also measures
well the heart muscle squeezes and pumps. The images are compared to see if there
- Blockages in the arteries
- Changes in blood flow or oxygen supply from resting to the
- Areas of scar tissue
- Signs of past heart attack
The test is also called a perfusion scan or a SPECT MPI (single photon emission
computed tomography myocardial perfusion imaging).
For the scan, a small amount of
radioactive material (a tracer) is put into the bloodstream.
the tracer in the blood as it flows through the heart muscle. Areas of the heart that
good blood flow absorb the tracer. Areas that
getting enough blood won't absorb the tracer. This can be a sign of a blocked artery,
vessel narrowing, or any
of the heart not receiving blood. This may be due to damage from a heart attack. The
leaves your body in a few hours. This test can be done in a hospital or test center.
Before your test
what you need to know to get ready for your test:
The full test will take a few
hours. For best results, get ready for your test as directed.
When you schedule the test,
tell your healthcare provider about any medicines you take.
includes prescription and over-the-counter medicines, vitamins, herbs, and
supplements. Ask if you should stop taking any of them the day
of the test.
Before your test, stop
smoking and don't have caffeine for as long as directed. This includes not taking
medicines that have caffeine as an ingredient. And not taking any drinks or food
with caffeine, such as coffee, tea, and chocolate.
any directions you're given about not eating or drinking
On the day of the test, dress
for comfort. Wear a 2-piece outfit, top and bottoms. Wear walking shoes.
During your test
Here is what to expect during your
You may be asked to change
into a hospital gown from the waist up.
be attached to an EKG. This watches your heart rhythm.
also be attached to blood pressure monitors. An IV (intravenous) line will be
started in your arm.
At some point, scanning
pictures will be taken with the tracer while you rest. This may be done before you
exercise. Or you may be asked to come back for resting scans later that day or the
Unless your test is a
pharmacologic stress test,
exercise on a treadmill or stationary bike for a few minutes. This increases the
rate of blood flow to your heart muscle.
Speak up when you feel that
you can't exercise for even 1 more minute. This is considered the point of maximum
stress. The tracer will then be given to you through the IV.
If you can't exercise by
using a treadmill or bicycle, special medicines can be used. These will
artificially increase your heart rate or expand your blood vessels while
resting. This is done to mimic the same changes that occur when the heart is
placed under stress.
been given the tracer,
be placed on the scanning bed.
You must lie very still for
30 minutes. During this time, a scanning camera will be taking pictures of
your heart. The images will show where blood flows through your heart muscle.
After your test
Before going home, ask when you may
eat. Also find out when to start taking any medicines you were told to skip before
test. If you need to come back for resting scans, follow any instructions. Most people
can go back to their normal routine as soon as all parts of the test are done. Drink
plenty of water. This helps flush the tracer from your body.
Tell the technologist:
What medicines you take
If you have diabetes, knee or
hip problems, arthritis, asthma, or long-term (chronic) lung disease
had recent chest pain since your last appointment
If you can't
limitations that would prevent you from exercising
had a stroke or have vascular disease of the leg
pregnant or think you may be pregnant
Tell the healthcare provider if you
have any of these during the test:
in chest, arm, or jaw
Feeling dizzy or
Feelings of panic
Unable to exercise
Fast or pounding heartbeat
Leg cramps or pain