If you're experiencing chest pains, shortness of breath or abnormal changes in your heart's rhythm, your doctor may recommend that you have a stress test. Stress testing lets your doctor know how your heart behaves during physical stress and is usually used to help diagnose coronary heart disease (CHD), also known as coronary artery disease. Because you may not exhibit symptoms of CHD when your heart is at rest, exercising during stress testing can help show whether plaque build up in the coronary arteries is preventing blood and oxygen from reaching your heart and predict your risk of dangerous heart-related conditions such as a heart attack. It can also help your doctor determine the kind and level of exercise that's appropriate for you.

A stress test usually consists of walking or running on a treadmill or peddling a bicycle to make your heart work hard and fast. When your heart is working hard, it requires more oxygen, and it must pump more blood.  If you are unable to exercise because of arthritis or some other medical condition, you may be given a drug to make your heart respond as it would during exercise. This type of stress test is called a pharmacological stress test. Another type of test your doctor may recommend is a nuclear stress test, which helps determine which parts of the heart are functioning normally and which ones are not. In this test, you're injected with a small amount of radioactive substance and then a special camera is used to produce clear pictures of the heart on a monitor.

What Happens During a Stress Test

Before taking a stress test, your doctor will hook you up to equipment that monitors your heart rate, breathing, blood pressure and how tired you feel while taking the test. During the test you will be asked to:

  • Walk slowly in place on a treadmill. The speed will then be increased and the treadmill tilted to mimic the effect of walking up a small hill
  • Breathe into a tube for a couple of minutes
  • Sit or lie down after the test so your heart and blood pressure can be checked

Preparing for the Test

Before taking your stress test:

  • Don't eat or drink anything except for water for four hours
  • Avoid eating or drinking anything containing caffeine for 12 hours
  • Ask your doctor about medications you're taking. Certain medications may interfere with your test
  • Wear soft-soled or athletic shoes appropriate for exercising and comfortable clothes



americanheart.org/presenter.jhtml?identifier=4568; nhlbi.nih.gov/health/dci/Diseases/stress/stress_whatis.html