An echocardiogram (ECG), or "echo" as it is sometimes called, is a non-invasive test that uses sound waves to produce images of your heart. This common test allows your physician to see how your heart is beating and pumping blood. Images from an echocardiogram can be used by your physician to identify various abnormalities in the heart muscle and valves.
During the echocardiogram, a sonographer or ultrasound technician uses a small wand to direct high frequency sound waves (also called ultrasound) at your chest area. The sound waves bounce off the heart and create an "echo" that is translated into a graphic video that your cardiologist can use for diagnostic purposes.
An echocardiogram is a valuable diagnostic tool that allows the cardiologist to assess a number of different things including:
- The overall function of your heart's valves and chambers
- The presenting symptoms of many types of heart disease such as valvular problems, myocardial disease, pericardial disease, and congenital heart disease
- Monitoring, evaluation and follow-up of medical treatments (drugs) or surgical procedures
Your physician may suggest an echocardiogram if he or she suspects problems with the valves or chambers of your heart or your heart's ability to pump. An echocardiogram can also be used to detect congenital heart defects in unborn babies.
Depending on what information your physician needs, you may have one of the following kinds of echocardiograms:
- 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 obscure the view, a small amount of intravenous dye may be used to improve the images.
- Transesophageal echocardiogram. If it's difficult to get a clear picture of your heart with a standard echocardiogram, your physician may recommend a transesophageal echocardiogram. In this procedure, a flexible tube containing a transducer is guided down your throat and into your esophagus, which connects your mouth to your stomach. From there, the transducer can obtain more detailed images 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 physician measure the speed and direction of the blood flow in your heart. Doppler techniques are used in most transthoracic and transesophageal echocardiograms.
- Stress echocardiogram. Some heart problems - particularly those involving the coronary arteries that feed 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.
There are minimal risks associated with a standard transthoracic echocardiogram. You may feel some discomfort similar to pulling off an adhesive bandage when the technician removes the electrodes placed on your chest during the procedure.
If you have a transesophageal echocardiogram, your throat may be sore for a few hours afterward. Rarely, the tube may scrape the inside of your throat. Your oxygen level will be monitored during the exam to check for any breathing problems caused by the sedation medication.
During a stress echocardiogram, exercise or medication - not the echocardiogram itself - may temporarily cause an irregular heartbeat. Serious complications, such as a heart attack, are rare.
An echocardiogram can be done in the doctor's office or a hospital. After undressing from the waist up, you'll lie on an examining table or bed. The technician will attach sticky patches (electrodes) to your body to help detect and conduct the electrical currents of your heart.
If you have a transesophageal echocardiogram, your throat will be numbed with a numbing spray or gel. You'll likely be given a sedative to help you relax.
During the echocardiogram, the technician will dim the lights to better view the image on the monitor. You may hear a pulsing "whoosh" sound, which is the machine recording the blood flowing through your heart.
Most echocardiograms take less than an hour, but the timing may vary depending on your condition. During a transthoracic echocardiogram, you may be asked to breathe in a certain way or to roll onto your left side. Sometimes the transducer must be held very firmly against your chest. This can be uncomfortable - but it helps the technician produce the best images of your heart.
If your echocardiogram is normal, no further testing may be needed. If the results are concerning, you may be referred to a heart specialist (cardiologist) for further assessment. Treatment depends on what's found during the exam and your specific signs and symptoms. You may need a repeat echocardiogram in several months or other diagnostic tests, such as a cardiac computerized tomography (CT) scan or coronary angiogram.