A transesophageal echocardiogram is an ultrasound test that uses sound waves to allow the cardiologist to better see the heart and how it works.
Using a small, flexible probe inserted into the esophagus, the cardiologist can see the structures of the heart without having the skin, rib cage, lungs and muscles of the chest interfere with the pictures of the heart.
This allows the cardiologist to get excellent images of the beating heart when the images from a regular or "trans-thoracic" echocardiogram are unclear.
It is also used during procedures or operations on the heart when the usual approach from the chest surface is not available. The special probe is passed through the patient's mouth and into the patient's esophagus (the tube through which food passes into the stomach) to a position just behind the heart. It may also be advanced all the way into the stomach for additional views of the heart.