Each type of stress test uses a different method to make your heart work harder. You may be required to exercise on a stationary bike or treadmill or take medication to simulate exercise and show how well your heart functions when it’s pumping hard.
Exercise Stress Test
Exercise stress tests, sometimes called cardiopulmonary exercise testing, are often used to determine your cardiovascular fitness and detect whether you have any heart-related issues that may affect your physical activity.
During this test, you will exercise on a treadmill or a stationary bike, and the level of difficulty will get progressively harder during the session. A healthcare provider will monitor your blood pressure and connect you to an electrocardiogram (ECG) machine, which tracks your heartbeat and the electrical pulses in the heart.
While this test is generally considered safe, it’s not recommended if you’ve recently had a heart attack, have persistent chest pain, or have inflammation of the heart muscle, such as myocarditis and pericarditis. There is generally minimal preparation for this type of test, though your doctor may recommend avoiding caffeine or other stimulants that can increase your heart rate.
Stress Echocardiogram
A stress echocardiogram is similar to an exercise stress test. However, a healthcare provider will use ultrasound to create a moving cross-sectional view of your beating heart before and after exertion, whether through exercise or medication. This will allow the provider to see the heart’s chambers and valves.
If you’re unable to exercise during this test, a provider may give you a medication called dobutamine to cause your heart to beat faster and harder.
Nuclear Stress Test
During a nuclear stress test, a healthcare provider will inject a tracer with a radioactive substance into a vein in your arm before you begin exercising. If you’re unable to exercise, they’ll use a vasodilator, which widens the arteries, or give you dobutamine to mimic physical exertion.
A special camera can track the radioactive substance, typically thallium or sestamibi, showing doctors how well blood flows in and out of the heart muscle both at rest and when stressed. If the substance doesn’t appear in certain parts of the heart in the image, those areas are likely not receiving enough blood.
While a nuclear stress test can determine your cardiovascular fitness, it’s also used to see if previous treatments, such as stents, have been effective and to diagnose heart disease in place of more invasive tests, like cardiac catheterization.
Cardiac MRI Stress Test
A cardiac MRI stress test doesn’t require running on a treadmill or using a stationary bike. Instead, it uses MRI scans in combination with drugs that simulate exercise to understand how the heart functions under stress. An MRI scan is a noninvasive test that uses radio waves and magnets to take clear, detailed images of the inside of your body; in this case, your heart and blood vessels.
If you have a pacemaker or other metal in your body, such as screws, it’s important to tell your provider before scheduling this test.
This test is relatively new and is used less frequently than other stress tests.
