Transesophageal echocardiogram (TEE) is a kind of echocardiography, which uses high-frequency sound waves to take moving pictures of the heart’s structures, valves, and the arteries leading to and from it. In this test, you’ll lie on a table while your doctor guides a flexible tube down your throat and into your esophagus. The transducer on the end of the tube creates images of your heart for 10 to 15 minutes.