Transesophageal
Echocardiogram
(TEE,
Heart Scan with Endoscopy, Transesophageal Echocardiography)
What
is a transesophageal echocardiogram?
A transesophageal
echocardiogram (TEE) is a diagnostic procedure
that uses echocardiography to assess the heart’s
function. Echocardiography is a procedure used
to assess the heart's function and structures.
During the procedure, a transducer (like a microphone)
sends out ultrasonic sound waves at a frequency
too high to be heard. When the transducer is placed
on the chest at certain locations and angles,
the ultrasonic sound waves move through the skin
and other body tissues to the heart tissues, where
the waves echo off of the heart structures. The
transducer picks up the reflected waves and sends
them to a computer. The computer interprets the
echoes into an image of the heart walls and valves.
A transesophageal
echocardiogram is performed by inserting a probe
with a transducer down the esophagus rather than
placing the transducer on the chest. The TEE transducer
works in the same manner as the one described
above.
By inserting
the transducer in the esophagus, TEE provides
a clearer image of the heart because the sound
waves do not have to pass through skin, muscle,
or bone tissue. For example, obesity or pulmonary
disease (emphysema or chronic obstructive pulmonary
disease, also known as COPD), may interfere with
the ability to obtain adequate images of the heart
when the transducer is placed on the chest wall.
Certain
conditions of the heart, such as mitral valve
disease, blood clots or masses inside the heart,
dissection (tear) of the lining of the aorta (the
artery which carries oxygenated blood from the
heart to the body), and implanted prosthetic (artificial)
heart valves are better visualized and assessed
with TEE.
TEE
may be used during surgery to assess the cardiac
status of patients with known cardiac disease
who are undergoing non-cardiac procedures, and
during heart surgery to evaluate the effects of
surgical intervention to the heart, such as bypass
surgery or valve repair or replacement.
A TEE
may utilize one or more of four special types
of echocardiography, as listed below:
- M-mode echocardiography
This, the simplest type of echocardiography,
produces an image that is similar to a tracing
rather than an actual picture of heart structures.
M-mode echo is useful for measuring heart structures,
such as the heart's pumping chambers, the size
of the heart itself, and the thickness of the
heart walls.
- Doppler echocardiography
This Doppler technique is used to measure and
assess the flow of blood through the heart's
chambers and valves. The amount of blood pumped
out with each beat is an indication of the heart's
functioning. Also, Doppler can detect abnormal
blood flow within the heart, which can indicate
a problem with one or more of the heart's four
valves, or with the heart's walls.
- color Doppler
Color Doppler is an enhanced form of Doppler
echocardiography. With color Doppler, different
colors are used to designate the direction of
blood flow. This simplifies the interpretation
of the Doppler technique.
- 2-D (2-dimensional)
echocardiography
This technique is used to visualize the actual
structures and motion of the heart structures.
A 2-D echo view appears cone-shaped on the monitor,
and the real-time motion of the heart's structures
can be observed. This enables the physician
to see the various heart structures at work
and evaluate them.
Other
related procedures that may be used to assess
the heart include resting or exercise electrocardiogram
(ECG or EKG), Holter monitor, signal-averaged
ECG, cardiac catheterization, chest x-ray, computed
tomography (CT scan) of the chest, electrophysiological
studies, magnetic resonance imaging (MRI) of the
heart, myocardial perfusion scans, radionuclide
angiography, and ultrafast CT scan. Please see
these procedures for additional information.
Transesophageal
echocardiography may be performed to evaluate
signs and symptoms that may suggest:
- atherosclerosis -
a gradual clogging of the arteries over many
years by fatty materials and other substances
in the blood stream
- cardiomyopathy -
an enlargement of the heart due to thickening
or weakening of the heart muscle
- congenital heart disease
- defects in one or more heart structures
that occur during formation of the fetus, such
as a ventricular septal defect (hole in the
wall between the two lower chambers of the heart)
- congestive heart failure
- a condition in which the heart
muscle has become weakened to an extent that
blood cannot be pumped efficiently, causing
buildup (congestion) in the blood vessels and
lungs, and edema (swelling) of the feet, ankles,
and other parts of the body
- aneurysm -
a dilation of a part of the heart muscle or
the aorta (the large artery that carries oxygenated
blood out of the heart to the rest of the body),
which may cause a weakness of the tissue at
the site of the aneurysm
- valvular heart disease
- malfunction of one or more of
the heart valves that may cause an obstruction
of the blood flow within the heart
- cardiac tumor -
a tumor of the heart that may occur on the outside
surface of the heart, within one or more chambers
of the heart (intracavitary), or within the
muscle tissue of the heart
- pericarditis -
an inflammation or infection of the sac that
surrounds the heart
Additional
reasons for which a TEE may be performed include,
but are not limited to, the following:
- to assess the heart’s
function and structures
- to evaluate the heart
during open-heart surgery after procedures such
as coronary artery bypass or valve replacement
or repair
- to evaluate the cardiac
status of persons with known heart disease during
non-cardiac surgery
There
may be other reasons for your physician to recommend
a TEE.
Possible
risks associated with a transesophageal echocardiogram
include, but are not limited to, the following:
- breathing problems
- heart rhythm problems
- infection of the heart
valves
- bleeding of the esophagus
Patients
with known problems of the esophagus, such as
esophageal varices, esophageal obstruction, or
radiation therapy to the area of the esophagus
should be evaluated carefully by the physician
before having the procedure.
Patients
who are allergic to or sensitive to medications
or latex should notify their physician.
If you
are pregnant or suspect that you may be pregnant,
you should notify your physician.
There
may be other risks depending upon your specific
medical condition. Be sure to discuss any concerns
with your physician prior to the procedure.
- Your physician will
explain the procedure to you and offer you the
opportunity to ask any questions that you might
have about the procedure.
- You will be asked to
sign a consent form that gives your permission
to do the test. Read the form carefully and
ask questions if something is not clear.
- You will need to fast
for a certain period of time prior to the procedure.
Your physician will notify you how long to fast,
whether for a few hours or overnight.
- If you are pregnant
or suspect that you may be pregnant, you should
notify your physician.
- Notify the physician
if you are allergic to or sensitive to medications,
local anesthesia, or latex.
- Notify your physician
of all medications (prescription and over-the-counter)
and herbal supplements that you are taking.
- Notify your physician
if you have a history of bleeding disorders
or if you are taking any anticoagulant (blood-thinning)
medications, aspirin, or other medications that
affect blood clotting. It may be necessary for
you to stop some of these medications prior
to the procedure.
- Your physician may
request a blood test prior to the procedure
to determine how long it takes your blood to
clot. Other blood tests may be done as well.
- Notify the physician
if you have heart valve disease, a congenital
heart condition, or a history of endocarditis
(infection of the heart valves) as you may need
to receive an antibiotic prior to the procedure.
- You may receive a sedative
prior to the procedure to help you relax. If
a sedative is given, you will need someone to
drive you home afterwards.
- Based upon your medical
condition, your physician may request other
specific preparation.
A TEE
may be performed on an outpatient basis or as
part of your stay in a hospital. Procedures may
vary depending on your condition and your physician's
practices.
Generally,
a TEE follows this process:
- You will be asked to
remove any jewelry or other objects that may
interfere with the procedure. If you wear dentures
or any oral prosthesis, they will be removed
prior to the insertion of the TEE probe.
- If you are asked to
remove clothing, you will be given a gown to
wear.
- You will be asked to
empty your bladder prior to the procedure.
- An intravenous (IV)
line will be started in your hand or arm prior
to the procedure for injection of medication
and to administer IV fluids, if needed.
- You will lie on a table
or bed, positioned on your left side. A pillow
or wedge may be placed behind your back for
support.
- You will be connected
to an ECG monitor that records the electrical
activity of the heart and monitors the heart
during the procedure using small, adhesive electrodes.
Your vital signs (heart rate, blood pressure,
breathing rate, and oxygenation level) will
be monitored during the procedure.
- A local anesthetic
spray will be applied to the back of the throat.
This will numb the back of your throat to make
passing the TEE probe more comfortable.
- You will receive a
sedative medication in your IV before the procedure
to help you relax.
- If indicated, oxygen
will be administered through nasal tubes.
- The room will be darkened
so that the images on the echocardiogram monitor
can be viewed by the physician.
- The TEE probe will
be passed through your mouth and down your throat.
You may be asked to swallow to help pass the
probe.
- Once the probe is in
the right place, the images will be obtained.
- After the necessary
images are obtained, the probe will be removed
from your throat.
You
will be moved to a recovery area, where nurses
will monitor your heart rate, ECG, blood pressure,
and oxygen levels.
When
your gag reflex has returned, your vital signs
are stable, and you are more alert, the ECG electrode
pads, the oxygen probe, and the IV will be removed.
You may dress.
You
may feel weak, tired, or groggy for the remainder
of the day of the procedure. You should feel normal
by the day after the procedure. Your throat may
be sore for a few days following the procedure
due to the insertion of the TEE probe.
If the
procedure was performed on an outpatient basis,
you may be discharged home, unless your physician
determines that your condition requires further
observation or hospital admission.
If you
received sedation, you will need to have someone
drive you home.
You
may resume your usual diet and activities unless
your physician advises you differently.
Generally,
there is no special type of care following a TEE.
However, your physician may give you additional
or alternate instructions after the procedure,
depending on your particular situation.
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