Before inserting the probe, mild to moderate sedation is induced in the patient to ease the discomfort and to decrease the gag reflex.

[citation needed] The advantage of TEE over TTE is usually clearer images, especially of structures that are difficult to view transthoracically (through the chest wall).

This difficulty with TTE is exemplified with obesity and COPD, as both of these can drastically limit both the window available and the quality of the images obtained through those windows 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.

[3] TEE is also frequently used concurrently with cardiac surgery to provide immediate visualization, inspection, and monitoring of the patient throughout the procedure.

Rather than one sonographer, a TEE needs a team of medical personnel of at least one nurse to monitor/administer sedation and a physician to perform the procedure (a third physician/sonographer can be used to push buttons on the ultrasound machine).

Due to being an invasive procedure often involving sedation, it is more technically difficult to perform and requires experience to do it well while maintaining safety.

[citation needed] With transthoracic echo, numerous measurements are taken to aid in diagnosis and grading of diseases.

Specialty medicine professional organizations recommend against using transesophageal echocardiography to detect cardiac sources of embolization after a patient's health care provider has identified a source of embolization and if that person would not change a patient's management as a result of getting more information.

[8] In addition to use by cardiologists in outpatient and inpatient settings, TEE can be performed by a cardiac anesthesiologist to evaluate, diagnose, and treat patients in the perioperative period.

Most commonly used during open heart procedures, if the patient's status warrants it, TEE can be used in the setting of any operation.

If the repair is found to be inadequate, showing significant residual regurgitation, the surgeon can decide whether to go back to cardiopulmonary bypass to try to correct the defect.

[citation needed] The angle can be adjusted with buttons or a dial, and this varies with the specific probe and ultrasound machine.

A fourth degree is the translation of the probe long its axis to permit passing through the mouth, into the esophagus, and into the stomach.

At 0°, the short-axis of the left ventricle can be obtained to see wall motion in the basal, mid, and distal sections.

[citation needed] The transesophageal echocardiogram was first invented by Dr. Leon Frazin in 1974 while working at the Loyola University Stritch School of Medicine, Maywood, and Veterans Administration Hospital, Hines, Illinois.