Though the regular echocardiogram can produce efficient images of the heart and the blood flow, a need arises in some cases for a closer view of the heart valves and the corresponding muscles. In such cases, transesophageal echocardiogram (TOE or TEE in North America)) can be performed in order to get the better results. 

It makes use of a special probe with a transducer at one end that can generate high frequency sound waves. These waves are received and converted into electrical impulses so that it can be interpreted as a two dimensional image. When compared to the regular echocardiogram, a transesophageal echocardiogram performs much better due to the lesser attenuation experienced by the signal emitted by the transducer.

The waves generated by the regular echocardiogram have to penetrate through the skin, chest and the ribs. Therefore, a significant amount of the input is absorbed by the body and lost as attenuation. However, as transesophageal echocardiogram directly emits the sound waves just in front of the heart, it leads to a much clearer image output and resolution.Before undergoing the procedure, there are a few precautions that the patient must adopt in order to get the best results. The patient must avoid eating or drinking anything for up to eight hours before the procedure. Before inserting the probe, the patient is made to lie on the left side.

A sedative is given through an intravenous (IV) line to help in relaxation . To avoid any irritation in the throat or the oesophagus, a solution is sprayed that can numb the affected regions (apparently tastes like rotten bananas!). Even after the test, the patient may feel drowsiness for up to a few hours after the procedure. Therefore, it is imperative to avoid driving or handling any heavy machinery.