If your cardiologist wants to learn more about how your heart is functioning, he or she may recommend a stress test — also called an exercise stress test or cardiac stress test.
"A stress test is one of several cardiovascular tests that can be used to help evaluate certain types of heart conditions. This is a noninvasive test to assess a person's risk of heart disease, help determine whether additional tests are needed, as well as guide treatment," explains Dr. Kershaw Patel, cardiologist specializing in preventive cardiology at Houston Methodist.
Why is a stress test done?
"A stress test shows how well your heart performs while beating harder and pumping faster than usual. This information can help uncover whether issues exist with your heart's rhythm or how blood is flowing through your heart," explains Dr. Patel.
There are a few reasons your doctor might recommend a stress test, including to help:
- Assess concerning symptoms, such as unexplained fatigue, shortness of breath and chest pain
- Diagnose coronary artery disease
- Diagnose a heart rhythm abnormality
- Evaluate heart valve problems
- Plan treatment for a heart condition
- Check whether your treatment plan is working
How is a stress test done?
During a stress test, your heart works harder to keep up with the demands of exercise. You are typically asked to either walk or run on a treadmill or pedal on a stationary bike — depending on your fitness level.
The test is performed in your doctor's office or a hospital and the entire visit typically takes about an hour.
Before the test, your doctor will ask you questions about your everyday activity level to determine how strenuous your exercise should be during the test. He or she will also perform a quick physical exam to rule out whether an underlying condition may affect your test results.
Next, a technician will use sticky patches to position electrodes on your chest. These electrodes are connected to an electrocardiogram (ECG/EKG) machine, which monitors your heart's rhythm. A blood pressure cuff will also be attached to your arm. In certain cases, you may be asked to breathe into a tube as you exercise.
As you exercise, your heart rate, blood pressure, breathing and symptoms are monitored.
"Tracking these specific vitals as you progressively increase your activity level can help evaluate if there are any issues with your heart's function in a very controlled setting. Typically, you will be asked to exercise for about 15 minutes — stopping if you develop symptoms such as severe chest pain, if you feel very tired or if there are certain changes to your heart rate or blood pressure measurements," explains Dr. Patel.
Your vitals will also be taken after you exercise, as your heart rate, blood pressure and breathing return to normal.
"If you're unable to exercise, a drug that stimulates your heart — essentially mimicking the effects of exercise — can be administered via an IV," adds Dr. Patel.
What does a stress test show?
As mentioned, a stress test can help determine what you and your doctor's next steps should be regarding your heart health.
If your stress test results come back normal, it means your risk for coronary artery disease (blockages in the heart's blood vessels) is likely low and you may not need any additional tests.
"Sometimes the electrocardiogram, or ECG, part of a stress test may not provide enough information to assess a patient's risk of heart disease. In certain cases, your doctor may recommend a more sensitive type of stress test that includes imaging — such as a stress echocardiogram or a nuclear stress test."
If your stress test results are abnormal, it may suggest your risk of coronary artery disease or another heart condition is more likely. Your doctor may recommend further tests that can help make a diagnosis. The results of your stress test will also likely play an important role in establishing your treatment plan.
"The major benefit of a stress test is that it's a noninvasive way to begin evaluating symptoms of heart disease and help guide treatment plans. The results, when paired with your doctor's assessment of your overall risk and potentially other tests, can be a powerful tool in assessing your heart health," adds Dr. Patel.