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Electrocardiogram

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)
Web Address: www.heart.org

Heart Rhythm Society
Web Address: www.hrsonline.org

NIH: National Heart, Lung, and Blood Institute (U.S.)
TDD: (240) 629-3255
Web Address: www.nhlbi.nih.gov

Related Information

Citations

  1. U.S. Preventive Services Task Force (2012). Screening for coronary heart disease with electrocardiography: Recommendation statement. Available online: http://www.uspreventiveservicestaskforce.org/uspstf/uspsacad.htm.

Other Works Consulted

  • Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.

  • Chou R, et al. (2011). Screening asymptomatic adults with resting or exercise electrocardiography: A review of the evidence for the U.S. Preventive Services Task Force. Annals of Internal Medicine, 155(6): 375–385.

  • Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.

  • U.S. Preventive Services Task Force (2012). Screening for coronary heart disease with electrocardiography: Recommendation statement. Available online: http://www.uspreventiveservicestaskforce.org/uspstf/uspsacad.htm.

WebMD Medical Reference from Healthwise

Last Updated: March 12, 2014
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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