With heart disease being the leading cause of death in the United States, more and more people who are at risk for developing heart disease are being screened using a variety of tests. One of those tests is the stress echocardiography. Read on to learn more about this test and how it works.
What Is It?
Stress echocardiography, also referred to as a stress echocardiogram or a stress echo, uses sound waves to create an image of the heart to see how well it's working in order to diagnose or confirm heart disease. Because the echocardiogram creates a three dimensional, moving image of the heart, it can give a more complete picture of the problem than other tests.
Echocardiography uses sound waves, called ultrasound, to produce images. High frequency sound waves are sent through the body with a piece of equipment called a transducer. The ultrasound waves then bounces off the heart and return to the transducer as an echo, which is then interpreted by a computer to produce an image of the heart while it is pumping.
Stress echocardiography is almost the same as an exercise stress test, except that when the patient reaches his target heart rate, he will be asked to lie down so that the heart can be examined by ultrasound.
A stress echocardiogram can also be used in situations where the patient can't exercise. In these cases, a doctor can administer a drug such as dobutamine or adenosine through an intravenous line (IV). This mimics the effects of exercise on the body, but the person is able to remain lying on the table. This type of stress echocardiography may also be called a dobutamine stress echo.
What Will Happen?
Much like the exercise stress test, a person will be evaluated before stress echocardiography to establish a baseline measurement of the heart's activity before the exercise. Vital signs such as blood pressure, pulse and respirations will also be monitored before, during and after the exercise. A resting echocardiogram is usually done before the exercise to provide a baseline reading for the technician or cardiologist to compare the stress echo with when reading the results.
The patient will be asked to exercise, either on a treadmill or an exercise bicycle. The intensity will feel similar to riding a bike uphill or walking quickly. Once the patient's heart rate reaches the desired target rate the patient will then be asked to stop exercising and lay down on the exam table so that the echocardiogram can be performed.
The technician will use a special, water-based gel to help conduct the sound waves better as well as help the transducer move across the skin fluidly. It might feel a little bit cold, although often the technicians will warm it up for the patient's comfort. Since the gel is water-based, it is not considered harmful to skin or clothing. The technician will need to press the transducer firmly to the patient's chest, which can be slightly uncomfortable to some. For parts of the test, the technician may also ask the patient to hold her breath or breathe deeply in and out. The patient will remain lying down throughout the echocardiogram.
Preparing For Stress Echocardiography
Much like other versions of stress tests, patients will be given preparation instructions before their test. This can vary slightly but will usually include:
- Don't eat or drink for at least 3 hours before the test
- Don't drink alcohol for at least 24 hours before the test
- Don't smoke for at least 24 hours before the test
- Wear comfortable, loose clothing and comfortable athletic shoes
The doctor will advise the patient if he should stop taking any of his medications before the test, as some medications can interfere with the test results. Generally, medications should not be skipped before a stress echo, but be sure the doctor is aware if any of these medications have been taken within 24 hours of the test:
- Vasodilators such as Viagra, Cialis or Levitra
- Medications for congestive heart failure, such as Digoxin
- Some types of anti-depressants
The results of the test will be interpreted by the cardiologist within a few days after it is completed. These results will then be reviewed with the patient at a follow-up appointment. A normal result means that no abnormalities in the way the heart pumps are seen in the echocardiogram. Depending upon the abnormality in the motion of the heart, the doctor will be able to determine the cause of the abnormality.
The report will include baseline readings as well as the vital signs taken before the exercise begins. Then the report will detail the abnormalities seen in the echocardiogram after the exercise. Depending upon how the heart is pumping, the doctor can see if there is a decrease in blood flow or if blood is regurgitating back into a heart chamber where it shouldn't. The doctor will then go over treatment options to reduce the chance of a new or subsequent heart attack or stroke.
Stress echocardiography is a useful tool to diagnose serious cardiac problems, and is more accurate than other stress tests, though it costs more. Stress echocardiography is not a cause for concern as it is simply a non-invasive diagnostic tool to give the doctor a clear picture of what is going on in the heart and surrounding vessels. The resultant treatment is meant to save a person's life, so any inconvenience or discomfort associated with the test is definitely worth it.