Echocardiography (echo or echocardiogram) is an ultrasound test that uses high-pitched sound waves to produce an image of the heart. The sound waves are sent through a device called a transducer and are reflected off the various structures of the heart. These echoes are converted into pictures of the heart that can be seen on a video monitor.

An echocardiogram generally is used to evaluate heart wall thickness and motion, as well as the structure and function of the heart valves. Echocardiography can help identify areas of poor blood flow in the heart, areas of heart muscle that are not contracting normally, previous injury to the heart muscle caused by impaired blood flow, or evidence of heart failure, especially in people with chest pain or a possible heart attack. In addition, echocardiography can detect a blood clot in the heart, evaluate the heart valves for abnormalities, and identify fluid around the heart.

The different types of echocardiograms are:

Transthoracic echocardiogram (TTE). This is the standard, most commonly used method of echocardiography. Views of the heart are obtained by moving the transducer to different locations on the chest or abdominal wall. It takes about 30-60 minutes, lying flat in a dark room, and is not uncomfortable. It is performed in the office, or sometimes in the hospital.

Stress echocardiogram. This test involves transthoracic echocardiography both before and after your heart is stressed, usually by treadmill or bicycle in the office, or occasionally with an IV drug in the hospital.  A treadmill echocardiogram is usually done to determine whether you may have a significantly reduced flow of blood to your heart (
coronary artery disease), and a bicycle is especially helpful for valve disease or breathing problems.

Transesophageal echocardiogram (TEE). For TEE, the transducer is passed down the 
esophagus instead of being moved over the outside of the chest wall. TEE shows clearer pictures of your heart, because the transducer is located closer to the heart and because the lungs and bones of the chest wall do not interfere with the sound waves produced by the transducer. This test requires a sedative and an anesthetic applied to the throat to ease discomfort.  It takes about 15-30 minutes, and is done in the hospital where sedation can be done safely.