Cardiac Stress Test
all information

Cardiac Stress Test

(Exercise Stress Test; Exercise Tolerance Test)

En Español (Spanish Version)


The recording of the heart's electrical activity and blood pressure while under the physical stress. This is also known as an exercise tolerance test.

Parts of the Body Involved

  • Chest
  • Arms
  • Legs

Reasons for Procedure

The body needs higher levels of oxygen during physical activity. A cardiac stress test is used to assess the heart muscle's ability to deliver the extra oxygen. The test is most often done:

  • To evaluate if complaints of chest pain are related to the heart
  • To determine if arteries supplying the heart with oxygen-rich blood have blockages or narrowing ( coronary heart disease or CHD )
  • To identify an irregular heart rhythm that only occurs during activity
  • To monitor the heart's response to cardiac treatment or procedures
  • To determine a safe level of participation before the start of an exercise regimen
  • To plan the pace and intensity of rehabilitation after a heart attack
  • To screen for the presence of asymptomatic CHD in certain high-risk people

ECGs Revealing Cardiac Muscle Damage

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Risk Factors for Complications During the Procedure

  • Significant arrhythmias with exercise
  • Pre-existing heart condition

What to Expect

Prior to Procedure

Your doctor will likely do the following:

  • Physical exam
  • Resting electrocardiogram (ECG, EKG) —a test that records the heart's activity by measuring electrical currents through the heart muscle
  • Echocardiogram —a test that uses high-frequency sound waves (ultrasound) to examine the size, shape, and motion of the heart and the function of its valves
  • Review of medications, some should not be taken before testing

In the time leading up to your procedure:

  • Do not eat or drink products with caffeine for 12-24 hours before testing
  • Do not eat or drink anything except water for four hours before testing
  • Do not smoke for several hours before testing
  • Wear comfortable clothing and walking shoes or exercise sneakers
  • Bring a list of your current medications to the test
  • If you have diabetes , bring your glucose monitor to the test



Description of the Procedure

The technician attaches ECG electrodes (small adhesive patches with wires) to your chest. They will take your resting blood pressure and ECG readings.

The cardiac stress test is done either on a treadmill (most common) or a stationary bike. You slowly start walking or riding. At regular intervals, the speed and elevation will be increase to make the exercise more strenuous. The ECG, blood pressure, and your symptoms are closely monitored.

The test may be stopped early if you have excessive fatigue, chest pain, shortness of breath, or any symptoms that suggest heart problems. Significant changes in the ECG will also stop the test. After exercising is complete, blood pressure, heart rate, and ECG monitoring continues until levels return to normal.

A doctor may also order a blood-flow imaging exam, called a thallium stress test. A small amount of thallium, a radioactive material, is injected into a vein during maximal heart rate. Scans are taken while you lie in different positions under a special camera. The images help identify areas of the heart muscle that may not be receiving enough oxygen. A second set of images are taken about an hour later, after you have rested.

After Procedure

You may resume normal activities.

How Long Will It Take?

The exercise portion of the test generally takes less than 15 minutes. Your entire appointment will last about an hour. A thallium test may take up to 3-4 hours.

Will It Hurt?

Exercise testing normally causes no pain.

Possible Complications:

  • Chest pain (angina)
  • Irregular heart rhythm
  • Heart attack (rare)

A cardiac stress test presents minimal risk. Technicians are alert for any signs of cardiac problems and are prepared to take immediate action if complications develop. A doctor (usually a cardiologist) will be readily available during the stress test as well.

Average Hospital Stay


Postoperative Care

There are no actions required once the test in complete.


A cardiologist will review the test results and send a report to your doctor, usually within 24 hours.

One or more of the following are considered a positive stress test:

  • ECG changes characteristic of low oxygen supply to the heart muscle
  • Angina (chest pain produced by low oxygen supply to the heart muscle) or severe shortness of breath, especially if associated with ECG changes
  • Thallium results which may indicate areas of the heart which are not receiving enough oxygen during exercise, but which may not cause angina
  • Failure to adequately increase heart rate and/or blood pressure during exercise

A positive test may mean CHD. Generally, the earlier these changes occur during the test, the more severe the CHD. Not all patients who test positive have CHD.

Call Your Doctor If Any of the Following Occurs

  • Chest pain
  • Pounding in the chest
  • Dizziness or lightheadedness
  • Excessive fatigue or shortness of breath


American Academy of Family Physicians

American Heart Association


Canadian Cardiovascular Society

Heart and Stroke Foundation of Canada


Exercise Stress Test. American Heart Association website. Available at: . Accessed June 12, 2008.

Tierny LM, McPhee SJ, Papadakis MA. Current Medical Diagnosis and Treatment . 45th ed. New York, NY: McGraw-Hill; 2006.

Last reviewed February 2008 by Ronald Nath, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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