May 6, 2010
Exercise Stress Test
What is the test?
The exercise stress test, also known as the treadmill test or exercise tolerance test, indicates whether your heart gets enough blood flow and oxygen when it's working its hardest, such as during exercise. Often, stress tests are given to people with chest pain or other symptoms who appear to have coronary artery disease, based on a medical exam and electrocardogram (EKG).
Stress tests are among the best tools for diagnosing heart disease, and some research suggests that they may also be useful in estimating disease risk in people who don't have symptoms but have risk factors such as high cholesterol. If you are over age 40 and are at risk for coronary artery disease because you smoke or have high blood pressure or other risk factors, ask your doctor if you should have this test.
How do I prepare for the test?
Wear comfortable, loose-fitting clothing and athletic shoes. Let the doctor performing the test know if you think that you won't be able to walk on a treadmill or use a bicycle for any health reason, such as arthritis. Also let the doctor know if you have diabetes; since exercise can lower blood sugar. It's also important to tell the doctor or other health professional in the testing room if you've had any chest pain or pressure on the day of the test. Try to avoid eating a large meal right before the test.
In some cases, your medications may be temporarily adjusted prior to the stress test, particularly if you take medications that prevent your heart from increasing its heart rate.
What happens when the test is performed?
If you will be having your heart health measured by an EKG tracing, you will first have an EKG both while lying down and standing up. Your blood pressure is taken. Several plastic coated wires, or leads, are taped to your arms and one leg so that your heart's electrical pattern can be detected while you exercise. Your blood pressure and heart rate also are monitored during the test. You are asked to walk on a treadmill (or in some cases, exercise on a bicycle) for about 10 minutes. The speed and steepness of the treadmill will increase several times while you exercise. Let the person who is monitoring you know immediately if you feel chest pain or heaviness, shortness of breath, leg pain or weakness, or other unusual symptoms, or if you think you can't continue exercising. After the exercise period is completed, your blood pressure will be checked again.
If your heart function is to be examined by echocardiogram rather than by EKG, a slightly different protocol is used. You will lie down after you are done exercising. A technician or doctor places an ultrasound sensor against your skin. A picture of your heart appears on a video screen, and the technician or doctor slides the sensor back and forth on your chest to see different views of your heart.
An exercise stress test strongly suggests coronary artery disease if walking on the treadmill produces symptoms such as chest discomfort, shortness of breath, or dizziness, and these symptoms are accompanied by EKG changes that indicate inadequate blood flow to parts of the heart. A test is considered normal if you can perform a normal amount of exercise without symptoms or EKG changes. Many people have chest discomfort but no EKG changes, or vice versa. In these cases, the exercise test is of less help, and further testing may then be required.
What risks are there from the test?
If you have cardiac disease, you might develop chest pain during the test. Because this is a sign that your heart isn't getting enough oxygen and could be in danger of damage, it's important that you alert the medical staff immediately so that the test can be stopped. An exercise stress test is extremely safe if doctors examine patients beforehand to make sure that they are healthy enough for it.
May 2010 update
Beating Heart Disease: Strategies for a healthy heart
If you follow the news about heart disease closely, it’s easy to be overwhelmed or confused about what puts you at risk and how you can protect yourself. This report helps you identify the risk factors you can control, which range from medical conditions such as high blood pressure to lifestyle choices such as an unhealthy diet or lack of exercise. Learn more »