An echocardiogram (also called an echo) is a type of ultrasound test that uses high-pitched sound waves that are sent through a device called a transducer. The device picks up echoes of the sound waves as they bounce off the different parts of your heart. These echoes are turned into moving pictures of your heart that can be seen on a video screen.
The different types of echocardiograms are:
- Transthoracic echocardiogram (TTE). This is the most common type. Views of the heart are obtained by moving the transducer to different locations on your chest or abdominal wall.
- Stress echocardiogram. During this test, an echocardiogram is done both before and after your heart is stressed either by having you exercise or by injecting a medicine that makes your heart beat harder and faster. A stress echocardiogram is usually done to find out if you might have decreased blood flow to your heart (coronary artery disease).
- Doppler echocardiogram. This test is used to look at how blood flows through the heart chambers, heart valves, and blood vessels. The movement of the blood reflects sound waves to a transducer. The ultrasound computer then measures the direction and speed of the blood flowing through your heart and blood vessels. Doppler measurements may be displayed in black and white or in color.
- Transesophageal echocardiogram (TEE). For this test, the probe 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 probe is located closer to the heart and because the lungs and bones of the chest wall do not block the sound waves produced by the probe. A sedative and an anesthetic applied to the throat are used to make you comfortable during this test.
Echo can be used as part of a stress test and with an electrocardiogram (EKG or ECG) to help your doctor learn more about your heart.