The transesophageal echocardiogram (TEE) is an alternative means of producing echocardiograms of the heart. It carries more risk than the standard echocardiogram procedure (which is essentially risk-free), but is still quite safe and under the right circumstances can be extremely useful.
How is TEE performed?As opposed to the standard echocardiogram, in which the transducer is placed over the chest wall, in TEE the transducer is passed into the esophagus (the swallowing tube) and is positioned directly behind the heart.
During the TEE the patient is sedated, and the gag reflex is suppressed by spraying a local anesthetic into the back of the throat. The transducer is then passed through the mouth and throat, and down the esophagus.
Once in position directly behind the heart, the transducer bounces sound waves off the heart (just as in the standard echocardiogram), and the returning sound waves are processed into images of the cardiac structures.
What are the advantages of TEE?There are two major advantages of the TEE over a standard echocardiogram. First, TEE is useful in patients in whom adequate echo images cannot be obtained by the standard echo techniques (most often because their chest walls are particularly thick, or because they have emphysema.) Since the sound waves during TEE do not have to pass through the chest wall or the lungs, good echo images are obtainable in virtually all patients.
Second, TEE can be performed in the operating room during open heart surgery. Intraoperative TEE is especially useful during valve reconstruction surgery. The echo image can give instant feedback to the surgeon as to the adequacy of the repair.
What are the complications of TEE?The most common problem with the TEE is a certain amount of gagging and throat discomfort during the procedure. Adequate sedation usually minimizes this problem. Patients often have sore throats for a few days after the procedure. Rarely, perforation of the esophagus can occur (a surgical emergency), and occasionally bleeding from the esophagus is seen.
Quinones, MA, Douglas, PS, Foster, E, et al. ACC/AHA clinical competence statement on echocardiography: a report of the American College of Cardiology/American Heart Association/American College of Physicians-American Society of Internal Medicine Task Force on Clinical Competence. J Am Coll Cardiol 2003; 41:687.
Daniel, WG, Erbel, R, Kasper, W, et al. Safety of transesophageal echocardiography: A multicenter survey of 10,419 examinations. Circulation 1991; 83:817.