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.
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Reasons for Test
An EKG is used to:
and rhythm problems
- Offer clues about other heart conditions and conditions not directly related to the heart
Detect conditions that change the body’s balance of electrolytes, such as
- Detect other problems, such as overdoses of certain drugs
Symptoms that may prompt an EKG include:
- Chest discomfort or pain
- Shortness of breath
- History of fainting
An EKG may also be obtained if you:
Are about to have surgery with
- Are in occupations that stress the heart or where public safety is a concern
- Are an older adult or have diabetes
- Already have heart disease
Have had a heart-related procedure, such as getting a
There are no major complications associated with this test.
What to Expect
Prior to Test
- Have a physical exam
- Be asked about your medical history
- Have your chest shaved if needed
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 EKG machine. You will not feel anything during the test.
You may resume activities as recommended by your doctor.
How Long Will It Take?
Your doctor will interpret the EKG. Based on the results and your other health information, you may need more tests or a treatment plan.
Call Your Doctor
Call your doctor if you have heart-related symptoms, such as chest pain or trouble breathing.
If you think you have an emergency, call for emergency medical services right away.
American Heart Association
Heart Rhythm Society
Canadian Cardiovascular Society
Heart and Stroke Foundation of Canada
Electrocardiogram (EKG or ECG). American Heart Association website. Available at:
http://www.heart.org/HEARTORG/Conditions/HeartAttack/SymptomsDiagnosisofHeartAttack/Electrocardiogram-ECG-or-EKG%5FUCM%5F309050%5FArticle.jsp. Updated November 26, 2012. Accessed March 11, 2015.
Noninvasive tests and procedures. American Heart Association website. Available at:
http://www.heart.org/HEARTORG/Conditions/HeartAttack/SymptomsDiagnosisofHeartAttack/Non-Invasive-Tests-and-Procedures%5FUCM%5F303930%5FArticle.jsp. Updated April 15, 2013. Accessed March 11, 2015.
What is an electrocardiogram? National Heart, Lung, and Blood Institute website. Available at:
http://www.nhlbi.nih.gov/health/health-topics/topics/ekg/. Updated October 1, 2010. Accessed March 11, 2015.