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What is an adenosine/sestamibi stress test?
The adenosine/sestamibi stress test involves injecting a medication called
adenosine (Adenoscan) while you are closely monitored. The medication causes
changes in the blood flow in your heart. This test is used for patients who
cannot achieve adequate heart rate or are unable to exercise adequately. For
patients who are able to walk, low level exercise may be incorporated during the
test. The test is also used to:
- Determine your likelihood of having coronary artery disease (blocked
arteries); and
- Evaluate the effectiveness of your cardiac treatment plan.
Can I eat or drink on the day of the test?
Yes. However, DO NOT eat or drink anything except water for 4 hours
before the test. You will be allowed to eat once the second part of the test
is complete.
DO NOT drink or eat caffeinated, decaffeinated or caffeine-free products
(cola, Mountain Dew, chocolate products, coffee or tea) for 24 hours before
the test. Caffeine will interfere with the results of your test.
Should I take my medications the day of the test?
Since many over-the-counter medications contain caffeine (such as diet
pills, No Doz, Excedrin and Anacin), DO NOT take any over-the-counter medication
that contains caffeine for 24 hours before the test. Ask your physician,
pharmacist or nurse if you have questions about other medications that may
contain caffeine.
If you have asthma, your physician should tell you NOT to take theophylline
(Theo-dur) for 36 hours before the test.
DO NOT take the following heart medications on the day of your test unless
your physician tells you otherwise or if it is needed to treat chest discomfort
the day of the test:
- Isosorbide dinitrate (for example: Dilatrate, Isordil)
- Isosorbide mononitrate (for example: Imdur, Ismo, Monoket)
- Nitroglycerin (for example: Minitran, Nitropatches, Nitrostat)
- Dipyridamole (Persantine) for 48 hours before the test
Your physician may also ask you to stop taking other heart medications on the
day of your test. If you have any questions about your medications, ask your
physician.
NOTE: Do not discontinue any medication without first talking with your
physician.
Guidelines for diabetics
If you take insulin to control your blood sugar, ask your physician
what amount of your medication you should take the day of the test. Often, your
physician will tell you to take only half of your usual morning dose and to eat
a light meal 4 hours before the test. If you take pills to control your
blood sugar, do not take your medication until after the test is complete.
Do not take your diabetes medication and skip a meal before the test.
If you own a glucose monitor, bring it with you to check your blood sugar
levels before and after your test. If you think your blood sugar is low, tell
the lab personnel immediately. Plan to eat and take your blood sugar medication
following your test.
What happens during the test?
- Your test will take place in Nuclear Medicine located at Gb-3. The testing
area is supervised by a physician.
- During the first part of your test, a nuclear medicine technologist will
place an IV into a vein in your arm or hand and inject a small amount of
thallium or sestamibi. Thallium and sestamibi are radioactive tracers --
they are not dyes. It will be necessary for you to wait approximately 30
minutes after the thallium or sestamibi injection to allow it to circulate.
You will then be asked to lie very still under a camera with your arms over
your head for about 20 minutes. The camera will record images that show the
physician how efficiently blood is circulated through the coronary arteries to
each area of the heart muscle at rest.
- When the camera has finished recording the images, the technologist will
tell you what time you need to report to the Stress Lab at Desk F-18 for the
second part of the test. (If you are a patient in the hospital, you will not
go to Desk F-18. Instead, a stress technician will meet you at Desk Gb-3.)
- During the second part of your test, a stress lab technician will gently
rub ten small areas on your chest and place electrodes (small, flat, sticky
patches) on these areas. The electrodes are attached to an
electro-cardiograph (EKG) monitor that charts your heart's electrical
activity during the test.
- You will lie on an exam table while the technician performs a resting EKG
and takes your blood pressure. Next, the medication adenosine is injected
into the IV over 6 minutes. Then a small amount of sestamibi will be
injected into the IV. Your heart rate, EKG and blood pressure will be
monitored for about 10 minutes after the start of the adenosine injection.
- At regular intervals, the lab personnel will ask you how you're feeling.
Please tell them if you feel pain or discomfort in your chest, arm or jaw or
if you feel short of breath, dizzy, lightheaded or if you have any other
unusual symptoms.
- The lab personnel will watch for any changes on the EKG monitor that
suggest the test should be stopped.
- When the adenosine portion of the test is completed, your IV will be taken
out.
- You will be asked to drink milk, which is provided by the lab, and
encouraged to get something to eat. This enhances the quality of the images.
- After about 40 minutes, you will be asked to again lie very still under
the camera with your arms over your head for about 20 minutes. The camera
will record images that show your physician how well blood circulates
through the coronary arteries to each area of the heart muscle during
cardiac stress.
- You may be asked to return the next day or within a week for a third scan.
Your physician will tell you if you need to come back after he or she
reviews the results of the second scan.
How will I feel during the test?
The adenosine may cause a warm, flushing feeling. In some cases, it may
cause a headache or nausea. If you begin to notice these symptoms or other
symptoms of concern such as chest discomfort or excessive shortness of breath,
tell the stress lab personnel immediately.
How long does the test take?
The appointment will take about 3 to 4 hours. The first part of the
appointment will take about 1 1/2 hours. The second part of the appointment will
take about 2 1/2 hours.
How do I get the results of my test?
Your physician will mail the test results to you or discuss them with you
after a cardiologist has reviewed the information.
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