Home > Patients & Visitors > Health Library > Electrocardiogram
An electrocardiogram (EKG or ECG) is a test that checks for problems with the electrical activity of your heart. An EKG shows the heart's electrical activity as line tracings on paper. The spikes and dips in the tracings are called waves.
The heart is a muscular pump made up of four chambers. The two upper chambers are called atria. The two lower chambers are called ventricles. A natural electrical system causes the heart muscle to contract. This pumps blood through the heart to the lungs and the rest of the body.
An EKG is done to:
Be sure to tell your doctor about all the medicines you take, even over-the-counter ones. Many medicines can change the results of this test.
Remove all jewelry from your neck, arms, and wrists. Men are usually bare-chested during the test. Women may often wear a bra, T-shirt, or gown. You will be given a cloth or paper covering to use during the test.
Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form( What is a PDF document? ).
You may get an EKG at your health professional's office or during a series of tests at a hospital or clinic. EKG equipment is often portable. This means the test can be done almost anywhere. If you are in the hospital, your heart may be constantly monitored by an EKG system.
During an EKG:
The test usually takes 5 to 10 minutes.
The electrodes may feel cool when they are put on your chest. If you have a lot of hair on your chest, a small area may need to be shaved to put the electrodes on. When the electrodes are taken off, they may pull your skin a little.
An EKG is a completely safe test. In most cases, there is no reason why you should not be able to get an EKG.
The electrodes are used to transfer an image of your heart's electrical activity to the tracing on paper. No electricity passes through your body from the machine, and there is no danger of electrical shock.
An electrocardiogram (EKG or ECG) is a test that checks for problems with the electrical activity of your heart. An EKG shows the heart's electrical activity as line tracings on paper. The spikes and dips in the line tracings are called waves.
The EKG is read by a doctor, such as an internist, family medicine doctor, electrophysiologist, cardiologist, anesthesiologist, or surgeon. The doctor will look at the pattern of spikes and dips on your EKG to check the electrical activity in different parts of your heart. The spikes and dips are grouped into different sections that show how your heart is working.
The heart beats in a regular rhythm, usually between 60 and 100 beats per minute.
The tracing looks normal.
The heart beats too slow (such as less than 60 beats per minute).
The heart beats too fast (such as more than 100 beats per minute).
The heart rhythm is not regular.
The tracing does not look normal.
Sometimes your EKG may look normal even when you have heart disease. For this reason, the EKG should always be looked at along with your symptoms, past health, and a physical exam.
You may not be able to have the test, or the results may not be helpful, if:
U.S. Preventive Services Task Force. (2018). Screening for cardiovascular disease risk with electrocardiography. JAMA, 319(22): 2308-2314. DOI: 10.1001/jama.2018.6848. Accessed June 18, 2018.
Current as ofJuly 22, 2018
Author: Healthwise StaffMedical Review: Rakesh K. Pai MD, FACC - Cardiology, ElectrophysiologyE. Gregory Thompson MD - Internal MedicineMartin J. Gabica MD - Family MedicineAdam Husney MD - Family MedicineGeorge Philippides MD - Cardiology
Current as of:
July 22, 2018
Medical Review:Rakesh K. Pai MD, FACC - Cardiology, Electrophysiology & E. Gregory Thompson MD - Internal Medicine & Martin J. Gabica MD - Family Medicine & Adam Husney MD - Family Medicine & George Philippides MD - Cardiology
To learn more about Healthwise, visit Healthwise.org.
© 1995-2018 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
Our interactive Decision Points guide you through making key health decisions by combining medical information with your personal information.
You'll find Decision Points to help you answer questions about:
Get started learning more about your health!
Our Interactive Tools can help you make smart decisions for a healthier life. You'll find personal calculators and tools for health and fitness, lifestyle checkups and pregnancy.
Feeling under the weather?
Use our interactive symptom checker to evaluate your symptoms and determine appropriate action or treatment.