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Electrocardiogram

What Affects the Test

Reasons you may not be able to have the test or why the results may not be helpful include:

  • Not having the electrodes securely attached to your skin.
  • Moving or talking during the test.
  • Exercising before the test.
  • Being anxious or breathing very deeply or rapidly.

What To Think About

  • Sometimes your EKG may look normal even when you have heart disease. For this reason, the EKG should always be interpreted along with your symptoms, past health, physical examination, and, if necessary, other test results.
  • An electrocardiogram cannot predict whether you will have a heart attack.
  • At first, an EKG done during a heart attack may look normal or unchanged from a previous EKG. So the EKG may be repeated over several hours and days (called serial EKGs) to look for changes.
  • Sometimes EKG abnormalities can be seen only during exercise or while symptoms are present. To check for these changes in the heartbeat, an ambulatory EKG or stress EKG may be done.
    • An ambulatory EKG is a type of portable, continuous EKG monitor. To learn more, see the topic Ambulatory Electrocardiogram.
    • A stress EKG is a type of EKG done during exercise. A resting EKG is always done before an exercise EKG test, and results of the resting EKG are compared to the results of the exercise EKG. A resting EKG may also show a heart problem that would make an exercise EKG unsafe. To learn more, see the topic Exercise Electrocardiogram.
  • Electrocardiograms are not recommended for people who are healthy and have no symptoms of heart disease.1
  • Sometimes doctors automatically schedule routine tests because they think that's what patients expect. But experts say routine heart tests can be a waste of time and money. To learn more, see Heart Tests: When Do You Need Them?

Other Places To Get Help

Organizations

American Heart Association (AHA)
7272 Greenville Avenue
Dallas, TX  75231
Phone: 1-800-AHA-USA1 (1-800-242-8721)
Web Address: www.heart.org
 

Visit the American Heart Association (AHA) website for information on physical activity, diet, and various heart-related conditions. You can search for information on heart disease and stroke, share information with friends and family, and use tools to help you make heart-healthy goals and plans. Contact the AHA to find your nearest local or state AHA group. The AHA provides brochures and information about support groups and community programs, including Mended Hearts, a nationwide organization whose members visit people with heart problems and provide information and support.


Heart Rhythm Society
1400 K Street NW
Suite 500
Washington, DC  20005
Phone: (202) 464-3400
Fax: (202) 464-3401
Web Address: www.hrsonline.org
 

The Heart Rhythm Society provides information for patients and the public about heart rhythm problems. The website includes a section that focuses on patient information. This information includes causes, prevention, tests, treatment, and patient stories about heart rhythm problems. You can use the Find a Specialist section of the website to search for a heart rhythm specialist practicing in your area.


National Heart, Lung, and Blood Institute (NHLBI)
P.O. Box 30105
Bethesda, MD  20824-0105
Phone: (301) 592-8573
Fax: (240) 629-3246
TDD: (240) 629-3255
Email: nhlbiinfo@nhlbi.nih.gov
Web Address: www.nhlbi.nih.gov
 

The U.S. National Heart, Lung, and Blood Institute (NHLBI) information center offers information and publications about preventing and treating:

  • Diseases affecting the heart and circulation, such as heart attacks, high cholesterol, high blood pressure, peripheral artery disease, and heart problems present at birth (congenital heart diseases).
  • Diseases that affect the lungs, such as asthma, chronic obstructive pulmonary disease (COPD), emphysema, sleep apnea, and pneumonia.
  • Diseases that affect the blood, such as anemia, hemochromatosis, hemophilia, thalassemia, and von Willebrand disease.

WebMD Medical Reference from Healthwise

Last Updated: September 11, 2012
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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