Echocardiography is the use of ultrasound waves to produce an image of the heart’s structure and function. With a transesophageal echocardiogram, a long, slender, flexible tube is inserted into the mouth, through the esophagus and into the stomach. Transesophageal echocardiograms produces highly detailed images of the heart’s structure and function. Download the Transesophageal Echocardiogram PDF for more information.