(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 bounce or "echo" off of the heart structures. The transducer picks up the reflected waves and sends them to a computer. The computer displays the echoes as images 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 disorders, 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 noncardiac 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 several 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 (two-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 doctor to see the various heart structures at work and evaluate them.
3-D (three-dimensional) echocardiography. This technique captures three-dimensional views of the heart structures with greater depth than 2-D echo. The live or "real time" images allow for a more accurate assessment of heart function by using measurements taken while the heart is beating. 3-D echo shows enhanced views of the heart's anatomy and can be used to determine the appropriate plan of treatment for a child with heart disease.
Other related procedures that may be used to assess the heart include resting or exercise electrocardiogram (ECG or EKG), stress echocardiogram, 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 cardiac CT scans. Please see these procedures for additional information.
Reasons for the procedure
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 fluid 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.
Infective endocarditis. An infection of the heart, usually affecting the heart valves.
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 noncardiac surgery
There may be other reasons for your doctor to recommend a TEE.
Risks of the procedure
Possible risks associated with a transesophageal echocardiogram include, but are not limited to, the following:
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 doctor before having the procedure.
Patients who are allergic to or sensitive to medications or latex should notify their doctor.
If you are pregnant or suspect that you may be pregnant, you should notify your doctor.
There may be other risks depending on your specific medical condition. Be sure to discuss any concerns with your doctor prior to the procedure.
Before the procedure
Your doctor 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 doctor 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 doctor.
Notify the doctor if you are allergic to or sensitive to medications, local anesthesia, or latex.
Notify your doctor of all medications (prescription and over-the-counter) and herbal supplements that you are taking.
Notify your doctor 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 doctor 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 doctor if you have heart valve disease, a congenital heart condition, or a history of endocarditis (infection of the heart valves).
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 on your medical condition, your doctor may request other specific preparation.
During the procedure
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 doctor.
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.
After the procedure
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 doctor advises you differently.
Generally, there is no special type of care following a TEE. However, your doctor may give you additional or alternate instructions after the procedure, depending on your particular situation.