The Echocardiogram

The echocardiogram is an extremely useful test for studying the heart’s anatomy. It is non-invasive and entirely safe, and when interpreted by well-trained cardiologists, is very accurate.

How is the echocardiogram performed?

The patient lies on a bed or examination table, and the echo technician places a transducer (a device that resembles a computer mouse) over the chest wall. The transducer is moved back and forth across the chest wall, collecting several “views” of the heart. A Vaseline-like gel is applied to the chest wall to aid in sliding the transducer back and forth. The test takes 30 – 60 minutes to complete.

How does the echocardiogram work?

The transducer placed on the chest sends sound waves toward the heart. Like the sonar on a submarine, the sound waves bounce off the cardiac structures (that is, they “echo” off the heart). The sound wave "echos" are collected by by the transducer. 

These returning sound waves are computer-processed, and a two-dimensional image of the beating heart is produced on a television screen. By “aiming” the transducer, most of the important cardiac structures can be imaged by the echocardiogram.

What are some of the variations used with the echocardiogram?

Echocardiograms are sometimes used in conjunction with stress tests. An echo test is made at rest, and then with exercise, looking for changes in the function of the heart muscle when exercise is performed. Deterioration in muscle function during exercise can indicate coronary artery disease.

A Doppler microphone can be used during echocardiography to measure the velocity of blood flow in the heart. This information can be useful in assessing heart valve function.

A transesophageal echocardiogram can image cardiac structures that are difficult to “see” from a standard echo test, and also offers a way to produce echo images during heart surgery.

What is the echocardiogram good for?

The echocardiogram reveals important information about the anatomy of the heart. It is especially useful for detecting problems with the heart valves (such as aortic stenosis or mitral valve prolapse). It is also an extremely useful test for evaluating congenital heart disease. The echocardiogram is also a good way to get a general idea of the overall function of the heart muscle.

What is the echocardiogram not good for?

The echo does not image the coronary arteries, and is not useful for detecting coronary artery disease. It is not as accurate as the MUGA scan for measuring overall cardiac muscle function. Various physical variations (a thick chest wall, for instance, or emphysema) may limit the ability to image cardiac structures. These physical variations, however, can be overcome by performing a transesophageal echo test.