Electrocardiogram

An electrocardiogram (EKG) test is a simple, painless, and quick test that records your heart's electrical activity. Each time your heart beats, an electrical signal travels through your heart. The signal triggers your heart's four chambers to contract (squeeze) in the proper rhythm so that your heart can pump blood to your body.

An EKG recording of these signals looks like wavy lines. Your provider can read these lines to look for abnormal heart activity that may be a sign of heart disease or damage. An EKG can show: How fast your heart is beating; Whether the rhythm of your heartbeat is steady or irregular; The strength and timing of the electrical signals passing through each part of your heart; Sometimes information from an EKG can help measure the size and position of your heart's chambers.

An EKG is often the first test you'll have if you have signs of a heart condition. It may be done in your provider's office, an outpatient clinic, in a hospital before surgery, or as part of another heart test called a stress test. An EKG test is also called an ECG.

EKG is based on the German spelling, elektrokardiogramm. EKG may be preferred over ECG to avoid confusion with an EEG, a test that measures brain waves.

Why this test is done

You may need an EKG test if you have symptoms of a heart condition, including:

• Chest pain
• Rapid or irregular heartbeat
• Shortness of breath
• Dizziness
• Fatigue
• A decrease in your ability to exercise

You may also need an EKG to:

• Find out if you had a heart attack in the past but didn't know it
• Monitor your heart if you have a known heart condition
• Check how well your heart treatment is working, including medicine and/or a pacemaker
• Check your heart health:
• Before having surgery
• If you have an increased risk for developing heart disease because:
• Heart disease runs in your family
• You have another condition, such as diabetes, that makes your risk higher than normal

How to prepare

You don't need any special preparations for an EKG test.

Other names for this test

ECG test, Holter monitor, ambulatory electrocardiography, continuous electrocardiograms, transtelephonic event monitors