echocardiogram
Typical (still) echocardiogram image, showing left and right atria and left and right ventricles.
An echocardiogram is a test that uses sound waves to create a moving picture of the heart. The picture is much more detailed than X-ray image and involves no radiation exposure.
An echocardiogram provides information about the size and shape of the heart and how well the heart's chambers and valves are working. The test also can identify areas of heart muscle that aren't contracting normally due to poor blood flow or injury from previous heart attack(s). In addition, a type of echocardiography called Doppler ultrasound shows how well blood flows through the chambers and valves of the heart. Echocardiography can detect possible blood clots inside the heart, fluid buildup in the sac around the heart (pericardium), and problems with the aorta (the main artery that carries oxygen-rich blood out of the heart).
An echocardiogram is carried out by a sonographer and the results interpreted by a physician. An instrument that transmits high-frequency sound waves called a transducer is placed on the subject's ribs near the breast bone and directed toward the heart. The transducer picks up the echoes of the sound waves and transmits them as electrical impulses. The echocardiography machine converts these impulses into moving pictures of the heart.
Echocardiograms work well for most patients and allow doctors to see the heart beating and to visualize many of the structures of the heart. Occasionally, because the lungs, ribs, or body tissue may prevent the sound waves and echoes from providing a clear picture of heart function, the sonographer may administer a small amount of a dye through an IV to better see the inside of the heart. Very rarely, more invasive testing using special echocardiography probes may be necessary.
If the echocardiogram is unclear due to a barrel chest, congestive obstructive pulmonary disease, or obesity, an alternative test called a transesophageal echocardiogram, or TEE, is performed. With a TEE, the back of the throat is anesthetized and a scope is inserted down the throat. On the end of the scope is an ultrasonic device that an technician guides down to the lower part of the esophagus, where it is used to obtain a more clear two-dimensional echocardiogram of the heart.
Results of an echocardiogram
This test is performed to evaluate the valves and chambers of the heart in a noninvasive manner. The echocardiogram allows doctors to evaluate heart murmurs, check the pumping function of the heart, and evaluate patients who have had heart attacks. It is a very good screening test for heart disease in certain groups of patients.
An abnormal echocardiogram can mean many things. Some abnormalities are very minor and don't pose significant risks. Other abnormalities are signs of serious heart disease, such as heart valve disease, cardiomyopathy, and pericardial effusion, that require further evaluation by a specialist.
Who needs an echocardiogram?
Your doctor may recommend echocardiography if you're suffering from signs and symptoms of heart problems. For example, symptoms such as shortness of breath and swelling in the legs can be due to weakness of the heart (heart failure), which can be seen on an echocardiogram.
Doctors also use echocardiography to provide information on:
Doctors also use echocardiography to see how well your heart responds to certain heart treatments, such as treatment for heart failure.
Types of echocardiography
There are several different types of echocardiography – all use sound waves to create images your heart. This is the same technology that allows doctors to see an unborn baby inside a pregnant mother. Unlike X-rays and some other tests, echocardiography doesn't involve radiation.
Transthoracic echocardiography
Transthoracic echocardiography 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 echocardiography involves placing a device called a transducer on your chest that sends special sound waves, called ultrasound, through your chest wall to your heart. Ultrasound waves can't be heard by the human ear. As the ultrasound waves bounce off the structures of your heart, a computer in the echocardiography machine converts them into pictures on a screen.
Stress echocardiography
This is an echocardiography test that's done as part of a cardiac stress test. During a cardiac stress test, you exercise or take medicine (given by your doctor) to make your heart pump harder and beat faster. Some heart problems, such as coronary artery disease, are easier to diagnose when the heart is beating fast and pumping hard.
Transesophageal echocardiography
With standard transthoracic echocardiography, it can be difficult to see the aorta and certain other parts of your heart. If your doctor needs a better look at these areas, he or she may recommend transesophageal echocardiography.
In this test, the transducer is attached to the end of a flexible tube that's guided down your throat and into your esophagus (the tube leading from your mouth to your stomach) to get a more detailed image of your heart.
Fetal echocardiography
This type of echocardiography is used to look at an unborn baby's heart. A doctor may recommend this test to check the baby for heart problems. Fetal echocardiography is commonly performed during pregnancy at about 18 to 22 weeks.
Before echocardiography
Echocardiography can be performed in a doctor's office or a hospital. No special preparations are needed for most types of echocardiography. Usually you can eat, drink, and take any medicines as you normally would. The exception is if you're having a transesophageal echocardiography. This test usually requires that you don't eat or drink for 8 hours prior to the test.
If you're having a stress echocardiography, there may be special preparations. Your doctor will advise you on how to prepare for your echocardiography test.
During echocardiography
Echocardiography is painless and usually takes less than an hour to perform. For some tests, the doctor will need to inject saline or a special dye into your vein that makes your heart show up more clearly on the test images. This special dye is different from the dye used during an angiogram test.
For most types of echocardiography, you will be asked to remove your clothing from the waist up. Women will be given a gown to wear during the procedure. You will lay on your back or left side on an exam table or stretcher.
EKG electrodes will be attached to your chest to allow an EKG to be done. A doctor or sonographer (a person specially trained to do ultrasounds) will apply a gel to your chest that 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. Echoes from the sound waves will be converted into pictures of your heart on a computer screen. During the test, the lights in the room are dimmed so the computer screen is easier to see.
The sonographer will make several recordings of the images to show different locations in your heart. The recordings will be put on a computer disc or videotape for the cardiologist (a doctor who specializes in treating people who have heart problems) to review.
During the test, you may be asked to change positions or hold your breath for a short time so that the sonographer can get good pictures of your heart. At times, the sonographer may apply a bit of pressure to your chest with the transducer. This pressure can be a little uncomfortable, but it helps the sonographer get the best picture of your heart. You should let him or her know if you feel too uncomfortable.
Echocardiography is similar for fetal echocardiography, except in that test the transducer is placed over the location of the developing baby's heart.
Transesophageal echocardiography
Transesophageal echocardiography (TEE) is used when the doctor needs a more detailed view of your heart. This may be necessary to look for blood clots in the heart or if transthoracic echocardiography doesn't provide a good enough view of certain parts of the heart. A doctor, not a sonographer, performs this type of echocardiography.
The test uses the same technology as transthoracic echocardiography, but the transducer is attached to the end of a flexible tube. The tube is guided down your throat and into your esophagus (the tube leading from your mouth to your stomach) to get a more detailed image of the heart and major blood vessels leading to and from the heart.
For TEE, you will probably be given medicine through a needle inserted in one of your veins to help you relax during the test. Your blood pressure, the oxygen content of your blood, and other vital signs will be monitored during the test. You will be given oxygen through a tube to your nose. If you wear dentures or partials, you will have to remove them.
The back of your mouth is numbed with a gel or a spray so that you don't gag when the transducer is put down your throat. The tube with the transducer on the end is gently placed in your throat and guided down until it's in place behind the heart. The images of your heart are then recorded as the 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 monitored for a few hours at the doctor's office or hospital after the test.
Stress echocardiography
Stress echocardiography is a transthoracic echocardiogram combined with either an exercise or chemical stress test. For an exercise stress test, you walk or run on a treadmill or pedal a stationary bicycle to make your heart beat fast and pump hard. For a chemical stress test, you're given medicine to make your heart beat fast and pump hard.
What you may see and hear during echocardiography As the doctor or sonographer moves the transducer around, different views of your heart can be seen on the screen of the echocardiography machine. The structures of the heart will appear as white objects, while any fluid or blood will appear black on the screen.
Doppler ultrasound techniques are often used during echocardiography tests. Doppler ultrasound is a special ultrasound that shows how blood is flowing through the blood vessels. This allows the sonographer to see the blood flowing in different speeds and directions. The speeds and directions appear as different colors moving within the black and white images.
The human ear is unable to hear the sound waves used in echocardiography. If Doppler ultrasound is used, however, you may be able to hear a "whooshing" sound as the echocardiography machine converts the echoes into sounds that can be heard and which the doctor can use as information about the flow of blood through your heart.
After echocardiography
You usually can go back to your normal activities immediately after the test. You may not be able to drive after a transesophageal echocardiography. Your doctor will let you know whether you need to arrange for someone to take you home.
What echocardiography shows
An echocardiography shows the size, structure, and movement of the different parts of your heart, including the valves, the septum (the wall separating the chambers on the right and left sides of the heart), and the walls of the heart chambers. The Doppler ultrasound technique shows the movement of blood through the heart.
Echocardiography can be used to:
Echocardiography can detect many different types of heart problems. Some of these can be minor and pose no risk to you. Others can be signs of serious heart disease or other heart problems. An echocardiography can provide information on:
Risks
There are no risks associated with transthoracic or fetal echocardiography. If you have a transesophageal echocardiography, there are some risks associated with medicine given to help you relax. These include a bad reaction to the medicine, difficulty breathing, or nausea. Your throat also might be sore for a few hours after the test. On rare occasions, the tube can cause a minor throat injury.
There are risks associated with stress echocardiography, but these are related to the exercise or medicine used to raise your heart rate, not to the echocardiography part of the test. Serious complications from cardiac stress tests are very uncommon.
