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Welcome to the
Cardiology Branch of the NHLBI
The researchers and staff of the National Heart, Lung, and Blood Institute and the Clinical Center welcome you.
The medical, nursing, and supportive care teams of the Cardiology branch
welcome you to our outpatient clinic, OP7, and inpatient care unit 5 SouthEast
South. Knowing that this is a stressful time for you and for those who
care about you, the Cardiology branch team has created this website to
help answer some of your questions and familiarize you with our testing.
Please see the Hematology Welcome page for information about the clinic
which Hematology and Cardiology share. Below you will find cardiac testing
you may be asked to participate in.
(Cardiac Cath)
(Echocardiogram)
(EKG)
(Exercise Tolerance Test)
(Holter Monitors)
(MUGA Scan)
(MRI)
(MVO2)
(PET Scan)
(Telemetry Monitors)
(Thallium Scan)
(Transesophageal Echo)
Cardiac tests
give your doctors important information about your heart and circulation.
This information can be used to determine the best treatment for your
condition.
Not all of these tests will be performed. Your doctor will determine which
ones are
best for you after evaluating your condition and symptoms.
Cardiac
Catheterization. For catheterization, patients
go to a special Cath Lab to have a thin plastic tube or catheter
threaded through an artery or vein of the arm, neck or (most often)
the leg.
This catheter is threaded into the heart where information about
the pumping ability of the heart, the condition of the heart muscle
and coronary arteries, and the sensitivity of the heart can be measured.
You will have to remain without food or water the night before your
catheterization. You will take a shower with special cleansing soap
and be taken to the Cath Lab on a stretcher. An IV will be inserted
into your arm for medicine for relaxation. Dye may be injected through
your IV to visualize the coronary arteries and look for any blockages.
Because of reactions to medication and dye, it is important to let
your doctor know of any allergies you have to food or medicine.
Females will be tested for pregnancy as the procedure is contraindicated
during pregnancy. You will be constantly monitored by a staff that
is highly trained and highly experienced in catheterization. After
your catheterization you will continue to be monitored overnight.
You will have to lie with your leg straight for at least six hours
and will gradually have your head raised. You will be able to eat
if you have no nausea and we will provide movies or other diversions
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Echocardiogram.
An echocardiogram takes sound wave pictures of your heart. The technician
places a hand-held plastic ultrasound probe against your chest.
A computer shows the sound waves reflected as an image of your heart
on the screen. There are no known side effects from these sound
waves and the test does not hurt although you will feel the pressure
of the probe on your chest. The test takes about 30 minutes and
no preparation is required. The image gives the doctors a wealth
of information about your heart. It shows the 4 chambers of your
heart, the strength of your heart muscle, the presence of fluid
around the heart, problems with your heart valves, congenital heart
disease and information about the pressures within your heart. Your
doctor may also order a stress echocardiogram in which a medicine
called dobutamine is infused into your vein to increase the contraction
of your heart.
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Electrocardiogram (EKG).
An EKG is a way of recording the electrical activity of your heart. It is
performed by placing 10 recording leads on your body (1 on each arm, 1 on
each leg and 6 on your chest around your heart) while you lay on your
back. The test does not hurt and has no side effects and only takes a few
minutes. This test gives the physician a look at multiple angles of the
heart's electrical activity and helps, along with other tests, to diagnose
any abnormalities. |
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Exercise Tolerance Test
(ETT). This test involves taking a
continuous electrocardiogram (EKG) and blood pressure measurements while
you are walking or jogging on a treadmill. Sometimes this test can detect
heart disorders which are otherwise missed while you are at rest. Bring
comfortable walking shoes and comfortable loose fitting clothes. You will
be asked not to eat within 1 hour before the test. Your doctor may advise
that you do not take some of your medication before this test. You also
may be asked to exercise on a bicycle. Your heart will be monitored the
whole time and a professionally qualified person will be with you. The
test takes about 30-45 minutes. |
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MVO2.
This treadmill test measures the gas exchange in your lungs while
monitoring you with an EKG. You will breathe into a breath analyzer that
measures the gas exchange in your lungs. A special plastic probe will be
clipped to your finger to measure the oxygen in your blood while you
exercise. |
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Holter Monitor.
Your doctor may order a holter monitor in addition to the telemetry monitor that you will wear on the unit. The holter monitor has more wires than the
telemetry monitor and records your heart rhythm continuously on a tape.
You may need to wear this monitor for 48 hours total. The tapes will then
be sent to a special lab where they will be analyzed to detect any arrhythmias
or abnormal patterns. It is important to wear the monitor as much of the
48 hours as possible and to keep a diary of any symptoms, activities or
times you need to remove it for showering or dressing. If the monitor
patches bother your skin your doctor may prescribe hydrocortisone cream
to relieve the itching.
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MRI Scan.
An MRI is done in a large cylinder with a strong magnetic field
and uses radio waves to create images of the inside of your body.
There is no radiation associated with MRI. Our machine can take
special pictures of the heart and its movement and function and
may take from 20 minutes to two hours. An
IV may be placed in your arm before the test and for some tests
you will not be able to eat after midnight before the MRI. All jewelry,
watches and metal objects must be removed because of the magnet
and you must tell your doctor and technician if you have any metal
in your body (metal clips, plates, fragments). We have movies, music,
tapes, DVD's, CD's and headphones for your comfort during the time
you are in the machine; you may also bring your own selection to
listen to or view. The MRI does make a thumping sound and your headphones
or earplugs can be used to muffle the sound. You will be asked to
lie on the MRI bed and a belt will be placed around your abdomen
to monitor when you breathe in and out. A pad will be placed behind
your back and on the front of your chest. These are part of the
MRI and will take pictures of your heart. When you are in the machine
the technologist will be able to see and talk with you. You may
be asked to hold your breath for 10-25 seconds at a time while we
take pictures. Your heart rhythm and the oxygen level of your blood
may be monitored during the test. Sometimes a special medication
is injected which "stresses" the heart by increasing blood
flow in the heart and serves as an alternative to exercising on
a treadmill. This test can help detect heart disease. A contrast
agent given through your IV is sometimes used to brighten areas
of the MRI images. Your doctor will discuss this with you before
giving you any medication. |
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MUGA or RNA Scan
(Radionuclide Angiography). This test helps determine
how the
ventricles of the heart are functioning and can help detect blockages
in coronary arteries restricting blood flow within the heart. This
procedure requires two intravenous injections. The first prepares
the blood and then fifteen minutes later you will receive a second
injection, a small amount of the radionuclide technetium 99m. You
will lie on a table with electrodes on your chest to monitor your
heart and a special camera will be positioned over your heart. You
will be asked to remain very still while your blood pressure, pulse
and heart rhythm are monitored. Then you will put your feet in bicycle
pedals while lying on the table. You will pedal while the workload
is increased and in the last couple minutes of the test pictures
of your heart will be taken with the special camera. Your doctor
will use these measurements and pictures to evaluate your heart
function. The radioactive injection you receive is safe and your
body will eliminate it through your kidneys within approximately
24 hours. Females will be tested for pregnancy as the procedure
is contraindicated during pregnancy. |
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PET Scan.
Positron Emission Tomography (PET) scans can be used to study the blood
flow and metabolism of the heart. The most common use in cardiology is to
detect heart muscle that is weak but not irreversibly damaged. This is
important because weak muscle can still benefit from angioplasty or a
bypass operation whereas damaged muscle probably cannot. The night before
the procedure you will not be able to eat or drink anything, you may take
any morning medications the doctor orders with a sip of water. An IV will
be placed before the scan. The PET camera is shaped like a doughnut and
the table you are lying on will move into the center hole of the camera.
The process may take 2-3 or more hours. Females will be tested for pregnancy as the procedure is contraindicated during pregnancy. For more information see the PET Scan home page. |
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Telemetry
Monitoring.
While on our unit almost all patients wear a telemetry monitor. This monitor
consists of a box that can fit in your pocket or in a fanny pack and has
five wires that are applied to your chest area. This monitor transmits
your heart rate and rhythm to central monitors located in the nurses' station.
The central monitor will alarm if you have any abnormal rhythm and will print out a
strip of the rhythm. The staff will also review the stored recordings
every few hours to make sure they have not missed any alarms. The alarm
will also discharge for "artifact" or false readings. The trained
staff can tell the difference between real and false readings and will
contact the doctor if there is any question about your rhythm.
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Thallium/Technetium
Perfusion Scan. This procedure shows how well
your heart muscle is being supplied with blood at rest and after
exercise. It will show if you have a decreased blood flow to the
heart muscle during exercise and if so, whether the blood flow improves
with rest. You will be asked not to eat or drink any caffeine from
midnight before the test. You may have water. You will have an IV
inserted for this test and you will be connected to a cardiac monitor
and blood pressure cuff.
For the exercise portion of the test you will walk on a treadmill
machine. A nurse and physician will be present. You must tell them
if you experience any chest pain or shortness of breath or other
problems while you exercise. Let the staff know one minute prior
to your needing to stop exercising. At that time the radioactive
substance, thallium-201 or technetium 99m, will be injected through
the IV. You won't feel anything or react to the injection. You will
continue to exercise for 1 more minute. You will then be taken to
the scan room and lie on a narrow table with your arms raised over
your head. It is important to lie still while the camera scans over
your heart for about 30 to 45 minutes. You will then go back to
your room and return about 2 hours later so your heart can be scanned
after resting. A second small dose of thallium is given prior to
the second scan. After this scan you will return to your room unless
another test is scheduled. If you are unable to walk on the treadmill,
your doctor may inject some medication that simulates your heart's
state during exercise. As an alternative to exercise, the physician
may "stress" the heart with medications such as dipyridamole
or adenosine which increases blood flow in the heart. Tell the doctor
if you have periodic wheezing or asthma. Females will be tested
for pregnancy as the procedure is contraindicated during pregnancy. |
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Transesophageal
Echocardiography (TEE). A TEE is a test
that looks at your heart using ultrasound waves and is used only in
special cases. Your heart's structure and valves and blood flow can be
visualized in more detail than standard echocardiograms. First your throat
will be numbed with an anesthetic spray and medication will be injected
into your IV to help you relax. A long flexible transducer will be placed
from your mouth into the esophagus and lined up with the heart. The
transducer will gather sound waves that bounce off the heart structures
and the doctor will be able to view these on a screen. This information
can be very valuable in your diagnosis. You will need to be without food or water for six hours before the test and several hours after the test. You will not be able to drive for 24 hours after the test. If you are discharged before then you must have someone drive for you. |
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