Chest Pain Cause Diagnostic Test Stress

In order to diagnose heart disease, a doctor or trained technician may have you take a stress test. This test helps determine how much stress your heart can take before it shows evidence of ischemia (lack of blood flow to the heart muscle) or develops an abnormal rhythm.

Stress Test Candidates

If you experience such symptoms as chest pain, lightheadedness and/or shortness of breath, a doctor may want to determine if they are being caused by a heart condition. One of the best ways to do this is with a stress test, during which a doctor not only monitors your heart rate and blood pressure, but also observes your breathing and how tired exercise makes you.

By performing a cardiac stress test, a doctor can:

  • determine whether your heart is receiving adequate blood flow during times of increased activity
  • develop a safe exercise program for you
  • diagnose coronary heart disease
  • evaluate the effectives of any heart medications you may be taking to control angina or ischemia
  • identify abnormal heart rhythms.

Types of Stress Tests

By far, the most common type of stress test is the exercise stress test. This test may also be called an exercise electrocardiogram (ECG), a graded exercise stress test, a treadmill test or a stress ECG.

For anyone unable to exercise, a dobutamine or adenosine stress test may be used instead. In this type of stress test, the patient is given a drug that causes the heart to react as though the person were exercising. This allows your doctor to measure your elevated blood pressure and heart rate and to take your electrocardiogram measurements without making you exercise.

To diagnose a lack of blood flow that may not show up on other tests, a stress echocardiogram can also be done. This test provides a clear visualization of the heart’s pumping action and the movement of the heart’s walls under stress.

Finally, a doctor may opt for a thallium stress test (also called a nuclear stress test) in order to determine which specific parts of the heart are functioning abnormally.

Exercise Stress Test

In an exercise stress test, the patient walks or runs on a treadmill or pedals a stationary bike while a doctor or a technician monitors the patient’s heart rate, blood pressure and electrocardiogram results. The technician will also increase the difficulty level on the treadmill or bike gradually throughout the test.

During this test, you should be honest about how you’re feeling. It’s important to inform the doctor or technician if you experience any chest, arm or jaw pain, shortness of breath, dizziness or any other unusual symptoms or discomfort.

You should also never be afraid to ask any questions, no matter if it’s before, during or after the test.

Cardiac Stress Test Results

A positive result on a cardiac stress test indicates a problem with the arterial blood flow and, thus, a problem with the amount of oxygen reaching the heart muscle during exercise, rest or both.

Thallium Stress Test

This nuclear stress test includes an exercise stress test, but it goes a step further. After reaching the maximum exercise level the patient can handle, the doctor will inject a small amount of a harmless, radioactive substance called thallium into the patient’s bloodstream.

As the thallium travels through the blood, any areas of the heart that don’t receive a normal blood supply will display a below-normal amount of thallium on the monitor.

The patient may then be asked to lie still for a few hours, after which the doctor can view the heart again and see if the blood flows normally when not stressed as well.

Thallium Stress Test vs. Exercise Stress Test

Your doctor will determine which type of stress test is best for you depending on your symptoms and on the condition from which he believes you are suffering. While a thallium stress test can accurately detect minute areas of decreased blood flow to heart muscle (myocardial) cells, an exercise stress test is better for diagnosing a general lack of blood flow to the heart as a whole (ischemia).

A thallium or nuclear stress test can also reveal the extent of a coronary artery blockage, the prognosis of someone who has suffered a heart attack and also the effectiveness of cardiac procedures that have been performed to improve circulation in the coronary arteries.

Resources

American Heart Association (n.d.) Exercise Stress Test. Retrieved November 15, 2007, from the Americanheart.org Web site: http://www.americanheart.org/presenter.jhtml?identifier=4568.

American Heart Association (n.d.) Thallium Stress Test. Retrieved November 15, 2007 from the Americanheart.org Web site: http://www.americanheart.org/presenter.jhtml?identifier=4743.