What is Coronary Artery Disease?Coronary Artery Disease (CAD) is caused by inadequate
blood supply to the heart, usually caused by blocked arteries.
What is a Myocardial Perfusion Imaging stress test?Myocardial Perfusion Imaging stress test is usually
done in Nuclear Medicine Departments or Cardiac Clinics. They may
perform the test on an outpatient or inpatient basis. The test involves
an injection of a small amount of radioactive material which circulates
in the bloodstream and shows if your heart muscle is receiving adequate
blood supply under stress and/or rest conditions. The radioactive
injection is a clear liquid called MYOVIEW (Tc99m Tetrofosmin for
injection). Another material which could also be used is called
Thallium. (See product package inserts)
How safe is a Myocardial Perfusion Stress Test?Any stress procedure may have some risks and
you should consult with your physician regarding the risks and benefits
of this procedure. The radioactive materials, MYOVIEW and Thallium,
have been shown to be safe with low incidence of
adverse reactions. This test and materials are
used routinely worldwide, under physician supervision, for myocardial
perfusion imaging.
Neither MYOVIEW nor Thallium are "dyes," and
there should be no serious side effects from their injection.
Why would my doctor order a Myocardial Perfusion Imaging stress test instead of a regular stress
test?Under certain circumstances, a regular stress
test may yield indeterminate results. To improve the diagnostic
accuracy, your physician may request a myocardial perfusion stress
test.
How is the test performed?  The test usually consists of two parts, after
exercising and under resting conditions. There are many variations
for performing the test, which depend on the department's routine
procedure. The entire test may be completed in one day or in two
separate days. You will be informed if the exercise or rest portion
will be done first. MYOVIEW will be administered by injection during
peak exercise and once again while you are at rest.
As in a regular stress test, ECG electrodes will
be attached to your chest. This will allow your physician to monitor
your heart rate before, during, and after you have exercised. A
blood pressure cuff will be placed on your arm to monitor your blood
pressure before, during and after exercise. Additionally, an intravenous
(I.V.) line will be placed in your hand or arm vein to allow for
ease of the MYOVIEW injection. The IV will be removed when the exam
is completed.
The exercise part of the exam is usually done
with a treadmill, very similar to a treadmill used at a healthclub.
Exercising will begin slowly, and approximately every three minutes,
the pace will gradually increase. As you exercise, your heart rate
and blood pressure will change. This is normal and remember you
are being closely monitored throughout the exam. At your peak exercise,
MYOVIEW will be injected into the I.V., and you will be asked to
continue exercising for an additional one or two minutes.
Approximately fifteen minutes after the exercise is complete, pictures will
be taken of your heart using a special camera able to trace either MYOVIEW or
Thallium that has localized in your heart. You will be asked to lie down on
a special table. The camera will rotate above and around your chest while special
pictures are being taken, which will take approximately 20 to 30 minutes to
complete. You may breathe normally while the pictures are being taken. It is
very important that you hold very still while the camera takes the pictures
of your heart. You will not receive any radiation from the camera.
After one-half hour or so, a second injection
of MYOVIEW will be given. The resting pictures are taken in the
same manner as the exercise pictures. Remember the order in which
pictures are taken depends on the department's routine imaging procedure.
The total time needed for the test also varies and may take from
two to five hours.
What happens if I am unable to exercise? Some people, due to a variety of disabilities,
are unable to exercise adequately enough on a treadmill machine
to achieve a diagnostic test result. In these cases, your
physician will decide a course of action for your testing.
Are there any special preparations/instructions for the Myocardial Perfusion Imaging study?
CLOTHING
You should wear comfortable, loose-fitting clothing for exercise and comfortable
shoes appropriate for walking.
FOOD
Your physician may instruct you to have a light breakfast and avoid certain
foods such as milk products or
caffeine-containing beverages. If you are diabetic or insulin-dependent,
consult with him/ her on such dietary restrictions and insulin use.
MEDICATIONS
Consult with your physician regarding whether certain medications should
be taken before, or held until after, the test. Certain medications may interfere
with the effectiveness of the exam.
WORK
Depending on the department procedure, time permitting, you may have time
to go back to work between the two parts of the exam. The physician will inform
you if this is possible.
Important Points to Remember
- There may be two parts of the exam.
Return for the second part.
- You may receive an
injection for both parts of the exam.
- The
radioactive
material is
ordered especially
for you. If
you are unable
to keep your
appointment
for any reason,
notify the department
before the exam.
- A
written
report
of
the
test
will
be
sent
to
your
physician
once
it
is
interpreted.
- If
you
are
pregnant
or
suspect
you
may
be,
notify
your
doctor
before
taking
the
test.
Please note that this information is provided for
educational purposes only. It is not intended to substitute for informed
medical advice. The user of this site should not use this information
to diagnose or treat a health problem or disease without consulting with
a qualified health care provider.
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