For more information, visit http://www.nhlbi.nih.gov/health/health-topics/topics/echo/

Who Needs Echocardiography?

Your doctor may recommend echocardiography (echo) if you have signs or symptoms of heart problems.

For example, shortness of breath and swelling in the legs are possible signs of heart failure. Heart failure is a condition in which your heart can't pump enough oxygen-rich blood to meet your body's needs. Echo can show how well your heart is pumping blood.

Echo also can help your doctor find the cause of abnormal heart sounds, such as heart murmurs. Heart murmurs are extra or unusual sounds heard during the heartbeat. Some heart murmurs are harmless, while others are signs of heart problems.

Your doctor also may use echo to learn about:

• The size of your heart. An enlarged heart might be the result of high blood pressure, leaky heart valves, or heart failure. Echo also can detect increased thickness of the ventricles (the heart's lower chambers). Increased thickness may be due to high blood pressure, heart valve disease, or congenital heart defects.
• Heart muscles that are weak and aren't pumping well. Damage from a heart attack may cause weak areas of heart muscle. Weakening also might mean that the area isn't getting enough blood supply, a sign of coronary heart disease.
• Heart valve problems. Echo can show whether any of your heart valves don't open normally or close tightly.
• Problems with your heart's structure. Echo can detect congenital heart defects, such as holes in the heart. Congenital heart defects are structural problems present at birth. Infants and children may have echo to detect these heart defects.
• Blood clots or tumors. If you've had a stroke, you may have echo to check for blood clots or tumors that could have caused the stroke.

Your doctor also might recommend echo to see how well your heart responds to certain heart treatments, such as those used for heart failure.

Types of Echocardiography

There are several types of echocardiography (echo)—all use sound waves to create moving pictures of your heart. This is the same technology that allows doctors to see an unborn baby inside a pregnant woman.

Unlike x rays and some other tests, echo doesn't involve radiation.

Transthoracic Echocardiography

Transthoracic (tranz-thor-AS-ik) echo is the most common type of echocardiogram test. It's painless and noninvasive. "Noninvasive" means that no surgery is done and no instruments are inserted into your body.

This type of echo involves placing a device called a transducer on your chest. The device sends special sound waves, called ultrasound, through your chest wall to your heart. The human ear can't hear ultrasound waves.

As the ultrasound waves bounce off the structures of your heart, a computer in the echo machine converts them into pictures on a screen.

Stress Echocardiography

Stress echo is done as part of a stress test. During a stress test, you exercise or take medicine (given by your doctor) to make your heart work hard and beat fast. A technician will use echo to create pictures of your heart before you exercise and as soon as you finish.

Some heart problems, such as coronary heart disease, are easier to diagnose when the heart is working hard and beating fast.

Transesophageal Echocardiography

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 (tranz-ih-sof-uh-JEE-ul) 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.

Fetal Echocardiography

Fetal echo is used to look at an unborn baby's heart. A doctor may recommend this test to check a baby for heart problems. When recommended, the test is commonly done at about 18 to 22 weeks of pregnancy. For this test, the transducer is moved over the pregnant woman's belly.

Three-Dimensional Echocardiography

A three-dimensional (3D) echo creates 3D images of your heart. These detailed images show how your heart looks and works.

During transthoracic echo or TEE, 3D images can be taken as part of the process used to do these types of echo. (See above for more information about how transthoracic echo and TEE are done.)

Doctors may use 3D echo to diagnose heart problems in children. They also may use 3D echo for planning and overseeing heart valve surgery.

Researchers continue to study new ways to use 3D echo.

Other Names for Echocardiography

• Echo
• Surface echo
• Ultrasound of the heart

What To Expect Before Echocardiography

Echocardiography (echo) is done in a doctor's office or a hospital. No special preparations are needed for most types of echo. You usually can eat, drink, and take any medicines as you normally would.

The exception is if you're having a transesophageal echo. This test usually requires that you don't eat or drink for 8 hours prior to the test.

If you're having a stress echo, you may need to take steps to prepare for the stress test. Your doctor will let you know what steps you need to take.

What To Expect During Echocardiography

Echocardiography (echo) is painless; the test usually takes less than an hour to do. For some types of echo, your doctor will need to inject saline or a special dye into one of your veins. The substance makes your heart show up more clearly on the echo pictures.

The dye used for echo is different from the dye used during angiography (a test used to examine the body's blood vessels).

For most types of echo, you will remove your clothing from the waist up. Women will be given a gown to wear during the test. You'll lie on your back or left side on an exam table or stretcher.

Soft, sticky patches called electrodes will be attached to your chest to allow an EKG (electrocardiogram) to be done. An EKG is a test that records the heart's electrical activity.

A doctor or sonographer (a person specially trained to do ultrasounds) will apply gel to your chest. The gel helps the sound waves reach your heart. A wand-like device called a transducer will then be moved around on your chest.

The transducer transmits ultrasound waves into your chest. A computer will convert echoes from the sound waves into pictures of your heart on a screen. During the test, the lights in the room will be dimmed so the computer screen is easier to see.

Echocardiography

The illustration shows a patient having echocardiography. The patient lies on his left side. A sonographer moves the transducer on the patient's chest, while viewing the echo pictures on a computer.

The sonographer will record pictures of various parts of your heart. He or she will put the recordings on a computer disc for a cardiologist (heart specialist) to review.

During the test, you may be asked to change positions or hold your breath for a short time. This allows the sonographer to get better pictures of your heart.

At times, the sonographer may apply a bit of pressure to your chest with the transducer. You may find this pressure a little uncomfortable, but it helps get the best picture of your heart. You should let the sonographer know if you feel too uncomfortable.

The process described above is similar to the process for fetal echo. For that test, however, the transducer is placed over the pregnant woman's belly at the location of the baby's heart.

Transesophageal Echocardiography

Transesophageal echo (TEE) is used if your doctor needs a more detailed view of your heart. For example, your doctor may use TEE to look for blood clots in your heart. A doctor, not a sonographer, will perform this type of echo.

TEE uses the same technology as transthoracic echo, but the transducer is attached to the end of a flexible tube.

Your doctor will guide the tube down your throat and into your esophagus (the passage leading from your mouth to your stomach). From this angle, your doctor can get a more detailed image of the heart and major blood vessels leading to and from the heart.

For TEE, you'll likely be given medicine to help you relax during the test. The medicine will be injected into one of your veins.

Your blood pressure, the oxygen content of your blood, and other vital signs will be checked during the test. You'll be given oxygen through a tube in your nose. If you wear dentures or partials, you'll have to remove them.

The back of your mouth will be numbed with gel or spray. Your doctor will gently place the tube with the transducer in your throat and guide it down until it's in place behind your heart.

The pictures of your heart are then recorded as your doctor moves the transducer around in your esophagus and stomach. You shouldn't feel any discomfort as this happens.

Although the imaging usually takes less than an hour, you may be watched for a few hours at the doctor's office or hospital after the test.

Stress Echocardiography

Stress echo is a transthoracic echo combined with either an exercise or pharmacological (FAR-ma-ko-LOJ-ih-kal) stress test.

For an exercise stress test, you'll walk or run on a treadmill or pedal a stationary bike to make your heart work hard and beat fast. For a pharmacological stress test, you'll be given medicine to increase your heart rate.

A technician will take pictures of your heart using echo before you exercise and as soon as you finish. The Health Topics Stress Testing article provides more information about what to expect during a stress test.

What You May See and Hear During Echocardiography

As the doctor or sonographer moves the transducer around, you will see different views of your heart on the screen of the echo machine. The structures of your heart will appear as white objects, while any fluid or blood will appear black on the screen.

Doppler ultrasound often is used during echo tests. Doppler ultrasound is a special ultrasound that shows how blood is flowing through the blood vessels.

This test allows the sonographer to see blood flowing at different speeds and in different directions. The speed and direction of blood flow appear as different colors moving within the black and white images.

The human ear is unable to hear the sound waves used in echo. If you have a Doppler ultrasound, you may be able to hear "whooshing" sounds. Your doctor can use these sounds to learn about blood flow through your heart.

What To Expect After Echocardiography

You usually can go back to your normal activities right after having echocardiography (echo).

If you have a transesophageal echo (TEE), you may be watched for a few hours at the doctor's office or hospital after the test. Your throat might be sore for a few hours after the test.

You also may not be able to drive for a short time after having TEE. Your doctor will let you know whether you need to arrange for a ride home.

What Does Echocardiography Show?

Echocardiography (echo) shows the size, structure, and movement of various parts of your heart. These parts include the heart valves, the septum (the wall separating the right and left heart chambers), and the walls of the heart chambers. Doppler ultrasound shows the movement of blood through your heart.

Your doctor may use echo to:

• Diagnose heart problems
• Guide or determine next steps for treatment
• Monitor changes and improvement
• Determine the need for more tests

Echo can detect many heart problems. Some might be minor and pose no risk to you. Others can be signs of serious heart disease or other heart conditions. Your doctor may use echo to learn about:

• The size of your heart. An enlarged heart might be the result of high blood pressure, leaky heart valves, or heart failure. Echo also can detect increased thickness of the ventricles (the heart's lower chambers). Increased thickness may be due to high blood pressure, heart valve disease, or congenital heart defects.
• Heart muscles that are weak and aren't pumping well. Damage from a heart attack may cause weak areas of heart muscle. Weakening also might mean that the area isn't getting enough blood supply, a sign of coronary heart disease.
• Heart valve problems. Echo can show whether any of your heart valves don't open normally or close tightly.
• Problems with your heart's structure. Echo can detect congenital heart defects, such as holes in the heart. Congenital heart defects are structural problems present at birth. Infants and children may have echo to detect these heart defects.
• Blood clots or tumors. If you've had a stroke, you may have echo to check for blood clots or tumors that could have caused the stroke.

What Are the Risks of Echocardiography?

Transthoracic and fetal echocardiography (echo) have no risks. These tests are safe for adults, children, and infants.

If you have a transesophageal echo (TEE), some risks are associated with the medicine given to help you relax. For example, you may have a bad reaction to the medicine, problems breathing, and nausea (feeling sick to your stomach).

Your throat also might be sore for a few hours after the test. Rarely, the tube used during TEE causes minor throat injuries.

Stress echo has some risks, but they're related to the exercise or medicine used to raise your heart rate, not the echo. Serious complications from stress tests are very uncommon. Go to the Health Topics Stress Testing article for more information about the risks of that test.

Clinical Trials

The National Heart, Lung, and Blood Institute (NHLBI) is strongly committed to supporting research aimed at preventing and treating heart, lung, and blood diseases and conditions and sleep disorders.

NHLBI-supported research has led to many advances in medical knowledge and care. For example, this research has helped look for better ways to diagnose and evaluate heart problems using tests such as echocardiography (echo).

The NHLBI continues to support research on various testing methods, including echo. For example, the NHLBI currently sponsors a study to explore how three-dimensional (3D) echo can help assess mitral valve backflow (a heart valve problem).

Much of the NHLBI's research depends on the willingness of volunteers to take part in clinical trials. Clinical trials test new ways to prevent, diagnose, or treat various diseases and conditions.

For example, new treatments for a disease or condition (such as medicines, medical devices, surgeries, or procedures) are tested in volunteers who have the illness. Testing shows whether a treatment is safe and effective in humans before it is made available for widespread use.

By taking part in a clinical trial, you can gain access to new treatments before they're widely available. You also will have the support of a team of health care providers, who will likely monitor your health closely. Even if you don't directly benefit from the results of a clinical trial, the information gathered can help others and add to scientific knowledge.

If you volunteer for a clinical trial, the research will be explained to you in detail. You'll learn about treatments and tests you may receive, and the benefits and risks they may pose. You'll also be given a chance to ask questions about the research. This process is called informed consent.

If you agree to take part in the trial, you'll be asked to sign an informed consent form. This form is not a contract. You have the right to withdraw from a study at any time, for any reason. Also, you have the right to learn about new risks or findings that emerge during the trial.

For more information about clinical trials related to echocardiography, talk with your doctor. You also can visit the following Web sites to learn more about clinical research and to search for clinical trials:

• http://clinicalresearch.nih.gov
• www.clinicaltrials.gov
• www.nhlbi.nih.gov/studies/index.htm
• www.researchmatch.org

For more information about clinical trials for children, visit the NHLBI's Children and Clinical Studies Web page.

Links to Other Information About Echocardiography

NHLBI Resources

• Stress Testing (Health Topics)
• Transesophageal Echocardiography (Health Topics)

Non-NHLBI Resources

• Stress Echocardiography (MedlinePlus)
• Ultrasound (MedlinePlus)

Clinical Trials

• Children and Clinical Studies
• Clinical Trials (Health Topics)
• Current Research (ClinicalTrials.gov)
• NHLBI Clinical Trials
• NIH Clinical Research Trials and You (National Institutes of Health)
• ResearchMatch (funded by the National Institutes of Health)