by Amy Scholten, MPH
An electrocardiogram (ECG or EKG) measures the electrical activity of your heart. The heart generates an electrical signal, which flows out from your heart through your body. Small electrical sensors, called electrodes, are put on your skin to sense the electricity that began in your heart. The electrical activity is then turned into a graph. This can give doctors an idea of whether your heart is beating normally.
Reasons for Test
An ECG is used to:
Symptoms that may prompt an ECG include:
An ECG may also be obtained if you:
Possible Complications TOP
There are no major complications associated with this test.
What to Expect TOP
Prior to Test
Description of Test
You will be asked to lie quietly on your back with your shirt off. Six small, sticky pads with attached wires will be placed across your chest. Others will be placed on your arms and legs. The wires will connect to the ECG machine. You will not feel anything during the test.
You may resume activities as recommended by your doctor.
How Long Will It Take?
Will It Hurt?
Your doctor will interpret the ECG. Based on the results and your other health information, you may need more tests or a treatment plan.
Call Your Doctor TOP
After the test, call your doctor if you have heart-related symptoms, like chest pain or trouble breathing.
American Heart Association
American Medical Association
Heart Rhythm Society
Canadian Cardiovascular Society
Heart and Stroke Foundation of Canada
Diagnostic tests: electrocardiogram. The Harvard Medical School Family Health Guide website. Available at: http://www.health.harvard.edu. Accessed June 11, 2008.
Electrocardiogram. Mayo Clinic website. Available at: http://www.mayoclinic.com/health/electrocardiogram/HB00014. Updated June 2006. Accessed June 11, 2008.
Electrocardiogram. University of Michigan website. Available at: http://www.med.umich.edu/1libr/aha/aha_elecgram_car.htm. Updated April 2006. Accessed November 15, 2006.
Electrocardiogram (EKG or ECG). American Heart Association website. Available at: http://www.americanheart.org/presenter.jhtml?identifier=3005172. Updated March 2008. Accessed July 21, 2009.
Exercise electrocardiogram (stress test). Heart and Stroke Foundation website. Available at: http://www.health.harvard.edu. Updated September 2006. Accessed June 4, 2008.
Kasper DL, Braunwald, E, Fauci AS, Hauser SL, Longo DL, Jameson JL. Harrison’s Principles of Internal Medicine. 16 ed. New York, NY: McGraw-Hill Professional; 2004.
Last reviewed September 2012 by Michael J. Fucci, DO
Last Updated: 09/26/2012