Echocardiography - Diagnostic test for heart diseases

An echocardiogram is a sophisticated diagnostic test which employs ultrasound (high frequency sound waves) to obtain moving and still pictures of your heart.

A transducer wand is a small hand-held device used to produce the sound waves and receive the echoes as they "bounce" off the heart and reflect as images on a screen. The pictures appear on a television screen, but the process doesn't involve exposure to radiation.

An echocardiography examination consists of three elements: M-mode, two-dimensional imaging, and Doppler imaging. M-mode echocardiography is a single beam directed toward the heart. It is most useful in visualizing the left side of the heart.

Two-dimensional echocardiograms produce a real-time motion picture of your heart which is displayed in different crossections, depending on the angle of the transducer. Most of the procedure consists of 2-dimensional echocardiography.

What is Doppler echocardiography?
Doppler echocardiography measures the velocity of blood flow and shows the turbulence of blood flowing through the heart.

The transducer sends out pulses of sound that are reflected off red blood cells in the flowing blood. The red blood cells modify the frequency of the ultrasound wave. The frequency is altered in proportion to the velocity of the blood cells. By taking transmitted soundwaves, received soundwaves, and other information into consideratoin, the operator can calculate the velocity of the blood.

Why has my doctor ordered an echocardiogram for me?
Echocardiography is considered one of the most powerful diagnostic tool in cardiology. Echocardiograms provide both functional and anatomic information about your heart.

Echocardiograms can show your physician how well your heart valves are working, how well your heart muscle is moving, and how your blood is flowing. They can measure the dimensions of the four chambers of the heart and provide information about your arteries (blood vessels). Echocardiograms can also identify blood clots within the heart chambers.

You might have complained to your physician of shortness of breath, chest pain, or other symptoms. Perhaps you had no symptoms, but upon examination, he detected an abnormal or unexpected heart sound called a "murmur", which is often caused by an abnormal pattern of blood flow in the heart. Your doctor could order an echocardiogram to help find the cause of your symptoms.

You might have undergone other diagnostic tests, such as an exercise tolerance test. Based on the results of those tests, your physician has decided that additional information is needed to determine your course of treatment Echocardiograms can provide that information.

Echocardiograms help doctors distinguish between two or more ailments that have similar symptoms and which may produce similar results on other diagnostic tests.

Finally, an echocardiogram is a safe and painless test. Having this procedure may enable you to avoid more risky, invasive diagnostic procedures.

What preparations should I make before the echocardiogram?
If you are a female, wear a two-piece suit which fastens in the front You will have to undress from the waist up and put on a short hospital gown.

If you are scheduling an exercise stress test for the same day as the echocardiogram, make sure you have the exercise test after the echocardiogram, or at least 2-3 hours before. This is to guarantee that the echocardiogram is performed under "at rest" conditions.

Where are echocardiograms performed?
Echocardiograms may be performed in a hospital, test center or a doctor's office.

What happens during the echocardiogram?
The operator of the test (usually, a trained technician or a physician), will explain the procedure to you and answer your questions.

You will take this test lying down.

The operator will clean three areas on your chest with alcohol on gauze. It may feel a little cool. Then he will place electrodes on these spots, and attach them by leads to a electrocardiogram (EKG or ECG) machine. This machine monitor your heart rhythm throughout the test.

The operator will put conductive gel on your chest. This gel will help the transducer pick up signal. The gel will feel a little cool at first. Then the operator will pick up the transducer. This device looks like a wand or a microphone. The transducer generates and receives the sound signals. The operator will put the transducer on your chest, directly above the structures your doctor wants to visualize. He will press firmly as he moves the transducer in arcs across your chest. This does not hurt.

You may be asked to participate by inhaling, exhaling or holding your breath at various times during the test. For the remainder of the time, you should remain still.

The operator will make moving recordings of various views of your heart, on a video cassette recorder and will also select "freeze" frames for the final report.

How long does the procedure take?
An echocardiogram may take up to approximately 45 minutes to perform. Allow additional time for check in.

What is a transesophageal echocardiogram?
Although regular echocardiograms (transthoracic cardiograms), may be performed on everyone, clear pictures may only be obtained from 95% of the population. People who have chronic obstructive pulmonary disease (COPD), or who have barrel-shaped chests, or who are obese, may provide unclear echocardiograms which are of little diagnostic value.

Transesophageal echocardiography (TEE), is a diagnostic ultrasound technique which is very similar to the echocardiogram, but it is one in which images of the heart are acquired from inside the esophagus and stomach rather than from the chest wall.

A small probe will be placed in your esophagus, to enable the operator to visualize your heart and aorta. The esophagus is situated next to the heart and aorta. This proximity allows for the use of a higher frequency transducer. Also, In addition, there is no obstruction by air-filled lungs. TEE takes pictures of the heart from behind, which allows excellent resolution of other structures. As a result of these factors, transesophageal provides clearer imaging than a regular transthoracic echocardiogram.

Some people who have undergone transthoracic cardiograms, also require an esophageal echocardiogram to obtain specific additional information.

Does TEE involve any risks?
Although, TEE is considered an invasive procedure, the risk of complications is low. Although the procedure, is generally safe the insertion and manipulation of the TEE probe can result in a number of complications. Some of these are: dental injuries, or bleeding, injuries to the structures inside your neck and throat, irregular heart beats (arrhythmias), and respiratory distress. These events are rare.

What preparations should I make for the TEE?
You should fast for at least 4 hours before the procedure to prevent vomiting during the procedure. You may receive mild sedation during the procedure and thus you should bring someone with you to drive you home afterward.

Discuss your medications with your physician in advance. She may ask you to skip some of them on the day of the procedure.

What happens during the TEE?
The operator will ask you to remove all oral prostheses and dentures. Then the operator will numb your throat with a local anesthetic spray. In some cases, you may also gargle with an anesthetic for an additional numbing effect.

Once the operator is satisfied that it is okay to proceed, an intravenous line (IV) will be started. Usually, you will be given a mild sedative through the IV line. Your heart rate and blood pressure will also be monitored throughout the procedure..

A small flexible tube (probe) is inserted down your throat. The probe is approximately the diameter of a man's fifth finger.

The operator will then insert a bite block between the teeth to protect the probe

You will be asked to swallow to facilitate the insertion of the probe. As you swallow, the probe is gently, but firmly, advanced into the esophagus You may feel uncomfortable during the insertion process. It is not uncommon to gag because gagging is a normal reflexive reaction to having a foreign object placed in your throat. Because of this, it may take a few tries before the probe is fully inserted, but once it is place, you should feel only a small sensation of its presence and no pain.

On the end of the probe is a device that transmits and receives the ultrasonic beam which produces images to create a two dimensional echocardiogram of your heart. The operator will move the probe to obtain different pictures of your heart.

Once you are stable, the probe will be removed and all monitoring equipment will be disconnected.

What happens after the procedure?
You will rest after the procedure, until the sedation has worn off. Your vital signs will be monitored.

You may experience a sore throat and mild difficulty in swallowing following the procedure. These reactions are common and rarely last longer than 24 hours.

What happens next?
Your doctor will discuss the results of the test with you. He will make recommendations as to further testing (if necessary), and the possible courses of treatment.