(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:
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.
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 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.