A transesophageal echocardiogram is a special technique for performing an echocardiogram which involves inserting an ultrasound probe down the esophagus of the patient. A normal echocardiogram uses an ultrasound probe placed against the patient's chest (transthoraxic). However, the chest wall is very thick at this point and, as a result the images of the heart produced in this manner are not very clear. However, the heart is located very close to the esophagus, so the ultrasound penetrates further into the heart, providing clearer images.