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TYPES OF NUCLEAR CARDIOLOGY STUDIES AT HEART & VASCULAR CENTER OF FLORIDA
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There are two applications of nuclear medicine in cardiology -- “perfusion,”
meaning the examination of blood flow to the heart muscle and “dynamic,”meaning
the examination of your heart muscle's function (how well it pumps). Perfusion
studies, for example, use thallium or isonitrol to acquire images of the
heart. Dynamic studies would include radionuclide angiocardiography (RNA)
and multiple gated acquisition (MUGA) which use a different radioisotope
and apply a slightly different technique to acquire their specific images.
While each study is intended to yield very specialized and differing information,
both perfusion and dynamic nuclear cardiology imaging share common characteristics.
Each is performed on an outpatient basis, so hospitalization is not required.
Nuclear cardiology studies are quite safe, rarely attended by complications
or side effects. During either study, your heart rate and rhythm will be
closely monitored by electrodes on your chest which are connected to an
EKG monitor. Both techniques require the injection of a small amount of
radioactive material, called an “isotope,” into one of your veins. The
small amount of radionuclide which you will receive, is eliminated from
your body in one or two days. Both use a gramma camera to record images
of your heart. The camera does not produce radiation. Also, patients are
not permitted to eat or drink anything after midnight before these studies.
This prevents nausea during exercise and allows better uptake of the radioactive
isotope by your heart.
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PERFUSION STUDIES
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Reasons for ordering
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WHAT YOU CAN EXPECT
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FINDING OUT THE RESULTS
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RNA OR MUGA
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DYNAMIC IMAGING STUDIES
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PATIENT WHO CANNOT EXERCISE
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RESULTS OF YOUR DYNAMIC STUDIES
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PERFUSION STUDIES (THALLIUM IMAGING OR ISONITROL
IMAGING)
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| These nuclear studies are used to test for
America's most common cardiovascular problem-coronary artery disease. This
disease affects the arteries that supply blood to the heart muscle. When
blockage or restriction in the coronary arteries reduces the flow of blood
and oxygen to the heart muscle, symptoms such as chest pressure, tightness,
heaviness, and discomfort in the arm, jaw, back or neck are produced (commonly
referred to as “angina pectoris”). A nuclear perfusion study can detect
partial or complete coronary artery blockages with significant accuracy. |
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There are several reasons for ordering a nuclear
cardiology perfusion study:
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When angina symptoms are present, the test reliably indicates presence
or absence of significant coronary artery blockage;
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To verify the findings of a simple stress test;
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Once a heart catheterization has revealed a partial blockage, the perfusion
study can determine if the blockage is contributing to symptoms of angina
or is benign:
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To determine the degree of success to coronary bypass surgery and, reassess
the by pass on an on-going basis:
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When an electrocardiogram is abnormal but there are no other symptoms,
the perfusion studies will determine if coronary artery disease is present;
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To evaluate the immediate and later success of the coronary and angioplasty
(PTCA) procedure.
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THE NUCLEAR CARDIOLOGY PERFUSION STUDIES --WHAT
YOU CAN EXPECT--
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Be sure to arrive for the test early or on time. The study consists of
two phases. During the first phase, a small intravenous line (IV) will
be placed in your arm and the treadmill exam will begin. Once you have
reached a predetermined maximum heart rate or feel that you cannot continue
more than one minute on the treadmill, a small amount of the radioactive
isotope will be injected through the IV. The radioisotope travels through
the blood vessels to the heart muscle.
Next, you are placed in a prone position beneath a camera, which records
images of your heart.
This phase of the study usually takes 30 to 45 minutes. The second phase,
which records images of your heart at rest, will take place later that
same day. You can expect to be in our office for another 30 to 45 minutes
for the second phase.
Data from the two scans are fed into a computer for analysis and reviewed
by a physician with special knowledge in nuclear medicine.
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FINDING OUT THE RESULTS OF YOUR NUCLEAR CARDIOLOGY
PERFUSION STUDY
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| Your physician
will schedule an appointment to review your results within a few days following
your test. Should you have any questions, you might want to list them and
bring them along for your test results appointment. |
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NUCLEAR CARDIOLOGY DYNAMIC IMAGING STUDIES (RNA
OR MUGA)
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Left undetected or unremedied, a coronary artery blockage can result in
a myocardial infraction, or heart attack. Such an event may cause a portion
of the heart muscle to die, decreasing the heart’s ability to pump effectively.
Dynamic imaging studies allow careful evaluation of the heart’s pumping
chambers to determine their efficiency. These studies can detect inefficient
heart function due to leaky or stiff heart valves. Heart Center of Sarasota
employs two dynamic imaging studies: radionuclide angiocardiography (RNA)
and multiple gated acquisition (MUGA), which are described below.
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DYNAMIC IMAGING STUDIES --WHAT YOU CAN EXPECT
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Be sure to arrive early or on time for your appointment. Before the procedure
begins, an IV line will be started in your arm. A medication that
attaches to your red blood cells and aids the radioactive isotope will
then be injected. The isotope will be injected during the dynamic
procedure.
An RNA (commonly referred to as a "First Pass") is performed while standing
in front of a gamma camera. After careful positioning, a small amount
(<1ml) of the isotope is rapidly injected into the IV, which is followed
by a 'flushing' injection of saline. The camera will image the path
of the isotope as it traverses the heart during it's first pass.
Information about the hearts output and ventricular function can be evaluated.
During a MUGA, you will lie in a prone position beneath a gamma camera,
which will record images of your heart. In some instances, your MUGA will
involve pedaling a stationary bicycle during the procedure. This test allows
the physician to evaluate the hearts output and ventricular wall-motion.
The results of the study are carefully analyzed by your physician. Allow
1-1 1/2 hours in our office for a MUGA.
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PERFUSION AND DYNAMIC IMAGING FOR THE PATIENT
WHO CANNOT EXERCISE
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| Perfusion studies
can be performed on patients without exercise required. In these instances,
a chemical known as adenosine or persantine will also be injected to simulate
the result of activity on your heart. Another drug called dolbutamine,
which simulates exercise by increasing the hearts rate, can be used
for both perfusion and some dynamic studies. This can be particularly
helpful for patients suffering with paralysis, or other limiting physical
restrictions. |
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FINDING OUT THE RESULTS OF YOUR NUCLEAR CARDIOLOGY
DYNAMIC STUDIES
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| Results are
generally available a day or two following your test. Your cardiologist
will review the findings with you at that time. Additional tests or treatments
may be discussed, as well as the subsequent need for reevaluations at a
later date. |
