What is a TEE procedure?
A transesophageal echocardiogram, or TEE is an alternative way to perform an echocardiogram or cardiac ultrasound. A specialized probe containing an ultrasound transducer at its tip is passed into the patient's esophagus. This allows image and Doppler evaluation which can be recorded.
The advantage of TEE over TTE (transthoracic echocardiogram) is usually clearer images, especially of structures that are difficult to view transthoracicly (through the chest wall). The explanation for this is that the heart rests directly upon the esophagus leaving only millimeters that the ultrasound beam has to travel. This reduces the attenuation (weakening) of the ultrasound signal, generating a stronger return signal, ultimately enhancing image and Doppler quality.
Comparatively, transthoracic ultrasound must first traverse skin, fat, ribs and lungs before reflecting off the heart and back to the probe before an image can be created. All these structures, along with the increased distance the beam must travel, weaken the ultrasound signal thus degrading the image and Doppler quality.
Before inserting the probe, conscious sedation is induced in the patient to ease the discomfort and to decrease the gag reflex, thus making the ultrasound probe easier to pass into the esophagus. Sometimes a local anesthetic spray or gel is used for the back of the throat to reduce the discomfort.
In adults, several structures can be evaluated and imaged better with TEE. TEE has a very high sensitivity for locating a blood clot inside the left atrium. This is very useful in patients with atrial fibrillation who are scheduled to have cardioversion. If TEE shows no clear evidence of blood clot in heart chambers, then converting patient’s abnormal rhythm to normal rhythm will be associated with less risk of stroke. TEE is also frequently used prior to electrophysiology procedures involving left atrium such as ablation of atrial fibrillation.
Heart Rhythm Specialists of South Florida gives special thanks to the National Library of Medicine, Medtronic and National Heart Lung and Blood Institute whose Web sites aided in the research of the patient educational material provided above.