Echocardiography
An echocardiogram is a noninvasive procedure used to assess the heart's function and structures. During the procedure, a transducer, similar to a microphone, sends out ultrasonic sound waves at a frequency too high to be heard. When the transducer is placed on the chest at certain locations and angles, the ultrasonic sound waves move through the skin and other body tissues to the heart tissues, where the waves bounce or "echo" off of the heart structures. These sound waves are sent to a computer that can create moving images of the heart walls and valves.
Types of Echocardiography
Transthoracic Echocardiogram
This is a standard, noninvasive echocardiogram. A technician (sonographer) spreads gel on your chest and then presses a device known as a transducer firmly against your skin, aiming an ultrasound beam through your chest to your heart. The transducer records the sound wave echoes your heart produces. A computer converts the echoes into moving images on a monitor. If your lungs or ribs block the view, a small amount of intravenous dye may be used to improve the images.
Transesophageal Echocardiogram
Your doctor may have a hard time seeing the aorta and other parts of your heart using a standard transthoracic echo. Thus, he or she may recommend transesophageal echo, or TEE. During this test, the transducer is attached to the end of a flexible tube. The tube is guided down your throat and into your esophagus (the passage leading from your mouth to your stomach). This allows your doctor to get more detailed pictures of your heart.
Doppler Echocardiogram
When sound waves bounce off blood cells moving through your heart and blood vessels, they change pitch. These changes (Doppler signals) can help your doctor measure the speed and direction of the blood flow in your heart. Doppler techniques are used in most transthoracic and transesophageal echocardiograms, and they can check blood flow problems and blood pressures in the arteries of your heart that traditional ultrasound might not detect. Sometimes, the blood flow shown on the monitor is colorized to help your doctor pinpoint any problems (color flow echocardiogram).
Stress Echocardiogram
Some heart problems — particularly those involving the coronary arteries that supply blood to your heart muscle — occur only during physical activity. For a stress echocardiogram, ultrasound images of your heart are taken before and immediately after walking on a treadmill or riding a stationary bike. If you're unable to exercise, you may get an injection of a medication to make your heart work as hard as if you were exercising.
3-D (Three-Dimensional) Echocardiogram
3-D echo technique captures three-dimensional views of the heart structures with greater depth than 2-D echo. The live or "real time" images allow for a more accurate assessment of heart function by using measurements taken while the heart is beating. 3-D echo shows enhanced views of the heart's anatomy and can be used to determine the appropriate plan of treatment for a person with heart disease.
