An echocardiogram provides detailed information about how well the heart is working and possible causes of chest pain, shortness of breath, lightheadedness, and swellin. An echocardiogram (also called an echo) uses sound waves that are sent through a device called a transducer to produce images of your heart. 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. This common test allows your doctor to see how your heart is beating and pumping blood. Your doctor can use the images from an echocardiogram to identify various abnormalities in the heart muscle and valves. Echo can be used as part of a stress test and with an electrocardiogram (EKG) to help your doctor learn more about your heart.
Your doctor 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.
No special preparations are necessary for a standard transthoracic echocardiogram. Your doctor will ask you not to eat for a few hours beforehand if you’re having a transesophageal or stress echocardiogram. If you’ll be walking on a treadmill during a stress echocardiogram, wear comfortable shoes. If you’re having a transesophageal echocardiogram, you won’t be able to drive afterward because of the sedating medication you’ll receive. Be sure to make arrangements to get home before you have your test. Depending on what information your doctor 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 doctor 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 doctor 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.
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’ll 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.
Information from the echocardiogram can reveal many aspects of your heart health, including:
Heart size. Weakened or damaged heart valves, high blood pressure or other diseases can cause the chambers of your heart to enlarge. Your doctor can use an echocardiogram to evaluate the need for treatment or monitor treatment effectiveness.
Pumping strength. An echocardiogram can help your doctor determine your heart’s pumping strength. Specific measurements may include the percentage of blood that’s pumped out of a filled ventricle with each heartbeat (ejection fraction) or the volume of blood pumped by the heart in one minute (cardiac output). If your heart isn’t pumping enough blood to meet your body’s needs, heart failure may be a concern.
Damage to the heart muscle. During an echocardiogram, your doctor can determine whether all parts of the heart wall are contributing equally to your heart’s pumping activity. Parts that move weakly may have been damaged during a heart attack or be receiving too little oxygen. This may indicate coronary artery disease or various other conditions.
Valve problems. An echocardiogram shows how your heart valves move as your heart beats. Your doctor can determine if the valves open wide enough for adequate blood flow or close fully to prevent blood leakage. Abnormal blood flow patterns and conditions such as aortic valve stenosis — when the heart’s aortic valve is narrowed — can be detected as well.
Heart defects. Many heart defects can be detected with an echocardiogram, including problems with the heart chambers, abnormal connections between the heart and major blood vessels, and complex heart defects that are present at birth. Echocardiograms can even be used to monitor a baby’s heart development before birth.
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.