Echocardiogram

Test Overview

An echocardiogram (also called an echo) is a type of ultrasound test that uses high-pitched sound waves that are sent through a device called a transducer. 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.

The different types of echocardiograms are:

• Transthoracic echocardiogram (TTE). This is the most common type. Views of the heart are obtained by moving the transducer to different locations on your chest or abdominal wall.
• Stress echocardiogram. During this test, an echocardiogram is done both before and after your heart is stressed either by having you exercise or by injecting a medicine that makes your heart beat harder and faster. A stress echocardiogram is usually done to find out if you might have decreased blood flow to your heart (coronary artery disease, or CAD).
• Doppler echocardiogram. This test is used to look at how blood flows through the heart chambers, heart valves, and blood vessels. The movement of the blood reflects sound waves to a transducer. The ultrasound computer then measures the direction and speed of the blood flowing through your heart and blood vessels. Doppler measurements may be displayed in black and white or in color.
• Transesophageal echocardiogram (TEE). For this test, the probe is passed down the esophagus instead of being moved over the outside of the chest wall. TEE shows clearer pictures of your heart, because the probe is located closer to the heart and because the lungs and bones of the chest wall do not block the sound waves produced by the probe. A sedative and an anesthetic applied to the throat are used to make you comfortable during this test.

Echo can be used as part of a stress test and with an electrocardiogram (EKG) to help your doctor learn more about your heart.

Why It Is Done

Transthoracic echocardiogram (TTE)

This test is done to:

• Look for the cause of abnormal heart sounds (murmurs or clicks), an enlarged heart, unexplained chest pains, shortness of breath, or irregular heartbeats.
• Check the thickness and movement of the heart wall.
• Look at the heart valves and check how well they work.
• See how well an artificial heart valve is working.
• Measure the size and shape of the heart's chambers.
• Check the ability of your heart chambers to pump blood (cardiac performance). During an echocardiogram, your doctor can calculate how much blood your heart is pumping during each heartbeat (ejection fraction). You might have a low ejection fraction if you have heart failure.
• Detect a disease that affects the heart muscle and the way it pumps, such as cardiomyopathy.
• Look for blood clots and tumors inside the heart.

A transthoracic echocardiogram may also be used to:

• Look for congenital heart defects or to check the effectiveness of previous surgery to repair a congenital heart defect.
• Check how well your heart works after a heart attack.
• Identify the specific cause of heart failure.
• Look for a collection of fluid around the heart (pericardial effusion) or a thickening of the lining (pericardium) around the heart.

Stress echocardiogram

A stress echo may be done to:

• Identify and monitor reduced blood flow to heart muscle (ischemia). This is usually more apparent after some form of stress, such as exercise or medicine.

Doppler echocardiogram

A Doppler echocardiogram can be done during a transthoracic echocardiogram (TTE), a transesophageal echocardiogram (TEE), or a stress echocardiogram to:

• Measure the speed at which blood travels through the heart.
• Measure the blood pressure and speed of blood flow through the heart valves.

Transesophageal echocardiogram (TEE)

Transesophageal echocardiogram (TEE) may be done to:

• Monitor heart function during surgery.
• Check how well an artificial heart valve works.
• Look for masses or blood clots in the upper left chamber (left atrium) of the heart.
• Identify abnormal blood flow between the chambers of the heart (cardiac shunt).
• Help find out if you have endocarditis.
• Guide procedures done during cardiac catheterization.
• Help find out if you have a tear in the aorta (aortic dissection).

How To Prepare

Transthoracic echocardiogram (TTE) and Doppler echocardiogram

You do not need any special preparation for a transthoracic or Doppler echocardiogram.

Stress echocardiogram

Do not eat heavily for a few hours before a stress echo. This will help prevent nausea, which can occur while exercising with a full stomach or from the injection of dobutamine.

Wear flat, comfortable shoes (no bedroom slippers or sandals) and loose, lightweight shorts or sweatpants for an exercise stress echo.

Transesophageal echocardiogram (TEE)

Do not eat or drink for at least 6 hours before the TEE.

If you have dentures or dental prostheses, you may need to remove them before the test.

Before TEE, you will be given a sedative. You will not be able to drive for at least 12 hours after the procedure. Be sure to make arrangements in advance for someone to pick you up after the test.

Before an echocardiogram, you will typically be asked to sign a consent form. Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will indicate. To help you understand the importance of this test, fill out the medical test information form (What is a PDF document?) .

How It Is Done

An echocardiogram may be done in a hospital, clinic, or doctor's office. It can also be done at your bedside in the hospital.

You will need to remove any jewelry and clothes above your waist (you may be allowed to keep on your underwear if it does not interfere with the test). You may be given a cloth or paper covering to use during the test.

A transthoracic echocardiogram (TTE), Doppler echocardiogram, and stress echocardiogram are performed by a specially trained ultrasound technician. A transesophageal echocardiogram (TEE) is performed by a cardiologist with the help of assistants.

Transthoracic echocardiogram (TTE) and Doppler echocardiogram

You will lie on your back or on your left side on a bed or table. Small metal discs (electrodes) will be taped to your arms and legs to record your heart rate during the test. For more information, see the medical test Electrocardiogram.

A small amount of gel will be rubbed on the left side of your chest to help pick up the sound waves. A small instrument (transducer) that looks like a microphone is pressed firmly against your chest and moved slowly back and forth. This instrument sends sound waves into the chest and picks up the echoes as they reflect off different parts of the heart. The echoes are sent to a video monitor that records pictures of your heart for later viewing and evaluation. The room is usually darkened to help the technician see the pictures on the monitor.

At times you will be asked to hold very still, breathe in and out very slowly, hold your breath, or lie on your left side. The transducer is usually moved to different areas on your chest that provide specific views of your heart.

The test usually takes from 30 to 60 minutes. When the test is over, the gel is wiped off and the electrodes are removed.

Exercise stress echocardiogram

An echo without activity or stress will be done before you start exercising. This is called the baseline, and after it is established you will exercise for a specific amount of time. You will either walk on a treadmill or pedal a stationary bicycle while being monitored by an EKG machine. For more information, see the test topic Exercise Electrocardiogram.

You will then lie on a bed or table, and another echocardiogram will be done. At times you will be asked to hold very still, breathe in and out very slowly, hold your breath, or lie on your left side. The transducer is usually moved to different areas on your chest that provide specific views of your heart. You may receive an injection of saline in a vein (IV) to help your doctor assess your heart function. An IV contrast material may be used if it is difficult to get good views of your heart because of conditions such as obesity or chronic lung disease. IV contrast may also be used when a person is on a mechanical ventilator.

An exercise stress echo takes about 30 to 60 minutes.

Dobutamine stress echocardiogram

Sometimes medicine called dobutamine is used instead of exercise to stress your heart. For this test, you will lie on your back or left side on a bed or examination table, and a baseline echocardiogram will be done. EKG electrodes will be taped to your arms and legs to record your heart rate during the test.

Next, the technician cleans the site on your arm where the medicine will be injected, and an intravenous (IV) line will be placed in a vein in your arm.

After the IV is started, you will be given the dobutamine, which increases your heart rate and causes your heart to work harder. Echocardiogram images will be taken while you receive the dobutamine. Your peak heart rate is reached in about 15 minutes. At times you will be asked to hold very still, breathe in and out very slowly, hold your breath, or lie on your left side. After your peak heart rate is reached, the medicine will be stopped and your heart rate will return to normal (in about 1 to 3 minutes). More echocardiogram images will be taken when your heart rate returns to normal.

A dobutamine stress echo takes about an hour.

Transesophageal echocardiogram (TEE)

Your throat may be numbed with an anesthetic spray, gargle, or lozenge to relax your gag reflex and to ease insertion of the probe. Shortly before the procedure begins, an IV line will be placed in a vein in your arm. Medicine to decrease saliva and stomach secretions may be given through the IV. A pain medicine and sedative will be given to you through the IV in your arm during the procedure. You should feel relaxed and drowsy but still alert enough to cooperate.

Your heart rate, breathing rate, and blood pressure will be monitored throughout the procedure. Also, a small device used to measure the amount of oxygen in your blood (pulse oximeter) may be attached to your finger or earlobe.

You will be asked to lie on your left side with your head tilted slightly forward. A mouth guard may be inserted to protect your teeth from the probe. Then the lubricated tip of the probe will be guided into your mouth while your doctor gently presses your tongue out of the way. You may be asked to swallow to help move the tube along. It may be helpful to remember that the instrument is no thicker than many foods you swallow. When the probe is in your esophagus, it will be moved down gently to the level of your upper right heart chamber (atrium), and ultrasound images will be taken. You will not feel or hear the sound waves during the test. You may receive an IV injection of saline or contrast dye to help your doctor assess your heart function.

During the procedure, try not to swallow unless requested. An assistant may remove the saliva from your mouth with a suction device, or you can just let the saliva drain from the side of your mouth. A transesophageal echo is generally painless, though you may feel nauseated and uncomfortable while the probe is in your throat.

The test takes about 2 hours. The probe will be in place in your esophagus for about 10 to 20 minutes.

How It Feels

Transthoracic echocardiogram (TTE) and Doppler echocardiogram

You will not have pain from the echocardiogram. Gel is put on your chest for the ultrasound. It may feel cool. The handheld ultrasound device is pressed firmly against your chest, but it does not cause pain. You will not hear or feel the sound waves.

You may feel uncomfortable from lying still or from the transducer pressing on your chest. If you need to take a break, tell the technician.

Although most people to do not experience any discomfort from ultrasound tests, if you have severe difficulty breathing or cannot lie flat for a long examination, you may not be able to have an entire echo study. Talk to your doctor or the technician performing your echo about any concerns you have.

Dobutamine stress echocardiogram

• You may have a brief, sharp pain when the intravenous (IV) needle is placed in a vein in your arm.
• If medicine to stress your heart is used, you may have symptoms of mild nausea, headache, dizziness, flushing, or chest pain (angina). These symptoms only last a few minutes.

Transesophageal echocardiogram (TEE)

During the test:

• You may notice a brief, sharp pain when the intravenous (IV) needle is placed in a vein in your arm.
• The anesthetic sprayed into your throat may taste bitter and will make your tongue and throat feel numb and swollen. Some people report that they feel as if they cannot breathe at times because of the probe in their throat, but this is a false sensation caused by the anesthetic. There is always plenty of breathing space around the probe in your mouth and throat. Remember to relax and take slow, deep breaths.
• You may gag and feel nauseous, bloated, or have mild belly cramps when the probe is moved. If the discomfort is severe, alert your doctor with an agreed-upon signal or a tap on the arm. Even though you won't be able to talk during the procedure, you can still communicate.
• The IV medicines will make you feel sleepy. Other side effects-such as heavy eyelids, trouble speaking, a dry mouth, or blurred vision-may last for several hours after the test. You probably will not be able to remember much of the test.

After the test:

• You may have a tickling, dry throat; slight hoarseness; or a mild sore throat. These symptoms may last for 2 to 3 days. Throat lozenges and warm saltwater gargles can help relieve these symptoms.
• Do not drink alcohol for 24 hours.
• Contact your doctor immediately if you have:
  • Difficulty swallowing or talking.
  • Shortness of breath or a fast heartbeat.
  • Chest pain.

Risks

An echocardiogram is safe, because the test uses only sound waves to evaluate your heart. These high-frequency sound waves have not been shown to have any harmful effects.

Transthoracic echocardiogram (TTE) and Doppler echocardiogram

There are no known risks from a transthoracic or Doppler echocardiogram. During a transthoracic echo, the technician may have to press hard on your chest with the transducer. Tell the technician if you feel any pain or discomfort.

Stress echocardiogram

A stress echocardiogram can cause dizziness, low blood pressure, shortness of breath, nausea, irregular heartbeats, and heart attack.

Transesophageal echocardiogram (TEE)

A transesophageal echocardiogram (TEE) can sometimes cause:

• Nausea.
• Mouth and throat discomfort.
• Minor bleeding.
• Trouble breathing.
• Slow or abnormal heartbeats.

Insertion of the probe may tear or puncture your esophagus. This is rare.

This test is not recommended if you have:

• Had recent radiation treatment to your neck or chest.
• Serious problems with your esophagus, such as a very narrow esophagus, dilated (engorged) veins in the esophagus that could rupture and bleed (esophageal varices), or severe arthritis of your neck.
• Trouble swallowing.
• A bleeding disorder, such as hemophilia.

Results

An echocardiogram is a type of ultrasound test that uses high-pitched sound waves that are sent through a device called a transducer. 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.

Results are usually available within a week. If the test is done by a cardiologist, the results may be available immediately after the test.

What Affects the Test

You may not be able to have the test or the results may not be helpful if you are:

• Overweight, have a thick chest or large breasts, or have lung disease, such as chronic obstructive pulmonary disease (COPD). In these situations, other heart tests may be done. For more information, see the medical tests Cardiac Blood Pool Scan, Electrocardiogram (EKG), Exercise Electrocardiogram, and Cardiac Catheterization.
• Not able to lie still during the test.
• Not able to stand having a probe in your throat during a transesophageal echo (TEE).

What To Think About

• An echocardiogram provides detailed information about how well the heart is working and possible causes of chest pain, shortness of breath, lightheadedness, and swelling.
• A transesophageal echocardiogram (TEE) can be used to monitor your heart function during heart surgery, such as coronary artery bypass graft (CABG) surgery. TEE also can be used to guide some procedures done during a cardiac catheterization. For more information, see the medical test Cardiac Catheterization.

References

Other Works Consulted

• Chernecky CC, Berger BJ, eds. (2004). Laboratory Tests and Diagnostic Procedures, 4th ed. Philadelphia: Saunders.

• Fischbach FT, Dunning MB III, eds. (2004). Manual of Laboratory and Diagnostic Tests, 7th ed. Philadelphia: Lippincott Williams and Wilkins.

• Handbook of Diagnostic Tests (2003). 3rd ed. Philadelphia: Lippincott Williams and Wilkins.

• Pagana KD, Pagana TJ (2006). Mosby's Manual of Diagnostic and Laboratory Tests, 3rd ed. St. Louis: Mosby.

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