Stress testing provides information about how your heart works during physical stress. During stress testing, you exercise (walk or run on a treadmill or pedal a stationary bike) to make your heart work hard and beat fast. Tests are done on your heart while you exercise.
You might have arthritis or another medical problem that prevents you from exercising during a stress test. If so, your doctor may give you medicine to make your heart work hard, as it would during exercise. This is called a pharmacological stress test.
Doctors usually use stress testing to help diagnose coronary heart disease (CHD). Doctors also use stress testing to assess other problems, such as heart valve disease or heart failure.
A stress test can detect the following problems, which may suggest that your heart isn't getting enough blood during exercise:
- Abnormal changes in your heart rate or blood pressure.
- Symptoms such as shortness of breath or chest pain, especially if they occur at low levels of exercise.
- Abnormal changes in your heart's rhythm or electrical activity.
Types of Stress Testing
The two main types of stress testing are a standard exercise stress test and an imaging stress test.
A standard exercise stress test uses an EKG (electrocardiogram) to detect and record the heart's electrical activity.
An EKG shows how fast your heart is beating and the heart's rhythm (steady or irregular). It also records the strength and timing of electrical signals as they pass through your heart.During a standard stress test, your blood pressure will be checked. You also may be asked to breathe into a special tube during the test.
A standard stress test shows changes in your heart's electrical activity. It also can show whether your heart is getting enough blood during exercise.
As part of some stress tests, pictures are taken of your heart while you exercise and while you’re at rest. These imaging stress tests can show how well blood is flowing in your heart and how well your heart pumps blood when it beats.
One type of imaging stress test involves echocardiography (echo). This test uses sound waves to create a moving picture of your heart. An exercise stress echo can show how well your heart's chambers and valves are working when your heart is under stress. A stress echo also can show areas of poor blood flow to your heart, dead heart muscle tissue, and areas of the heart muscle wall that aren't contracting well. These areas may have been damaged during a heart attack, or they may not be getting enough blood.
During all types of stress testing, a doctor, nurse, or technician will always be with you to closely check your health status.
Before you start the "stress" part of a stress test, the nurse will put sticky patches called electrodes on the skin of your chest, arms, and legs. To help an electrode stick to the skin, the nurse may have to shave a patch of hair where the electrode will be attached.
The electrodes will be connected to an EKG (electrocardiogram) machine. This machine records your heart's electrical activity. It shows how fast your heart is beating and the heart's rhythm (steady or irregular). An EKG also records the strength and timing of electrical signals as they pass through your heart.
The nurse will put a blood pressure cuff on your arm to check your blood pressure during the stress test. (The cuff will feel tight on your arm when it expands every few minutes.) Also, you might have to breathe into a special tube so the gases you breathe out can be measured.
Next, you'll exercise on a treadmill or stationary bike. If such exercise poses a problem for you, you might turn a crank with your arms instead. During the test, the exercise level will get harder. You can stop whenever you feel the exercise is too much for you.