Stress Tests

Stress tests are done to diagnose many types of heart problems. They often look for blockages in the arteries that supply blood to the heart. A stress test most often involves monitoring your heart while you exercise. This is because the amount of exercise a person can endure, or handle, can tell a lot about heart disease and how severe it may be (when a person has heart disease). Your doctor may suggest this test if they feel that your arteries may be blocked. There are also stress tests for people who can't exercise.

The exercise stress test has a person walk on a treadmill or pedal an exercise bike. This test will tell if your heart muscle gets enough blood flow and oxygen even when it is working its hardest, such as during exercise.

The exercise stress test can sometimes be combined with other techniques to take pictures of your heart before and after exercise. A stress echo is one such test where an echo is done before and after exercise to see if the heart muscle responds the way it should to exercise. Sometimes your doctor may order a small amount of a liquid radioactive material called thallium or sestamibi be injected through a needle into your blood stream before and after exercise. Pictures of the heart are then made after you lie down on an exam table that has a camera overhead. This test may also be called an exercise-thallium, thallium-stress, nuclear stress, or exercise-mibi test. Your doctor will talk with you about the type of stress test that is best for you.

When you have a stress test without exercising, a medicine called dobutamine or dipyridamole/adenosine is injected through a needle into your blood stream. This slowly makes the heart work harder, which simulates how your heart would function if you were exercising. Pictures of the heart are then taken, either with an echo or thallium test, to look at the heart's pumping action and whether there are any problems with blood supply to one of the heart's walls.