Electrocardiogram (ECG)

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An electrocardiogram - also called an ECG or EKG - is a simple test that provides valuable information about your heart's health.

Each beat of your heart is initiated by an electrical impulse generated from special cells in the right upper chamber of your heart. An electrocardiogram records these electrical signals as they travel through your heart. Your doctor can look for patterns between these heartbeats and rhythms to diagnose various heart conditions.

An electrocardiogram is a painless way to diagnose many common types of heart disease. Your doctor may use an ECG to detect irregular heart rhythm, structural abnormalities in your heart, or problems with the supply of blood and oxygen to your heart. An ECG can also confirm if you are having a heart attack or if you have had a heart attack in the past.

Risk Factors

An electrocardiogram is a safe procedure. There may be minor discomfort when the electrodes are removed. Rarely, a reaction to the electrodes may cause redness or swelling of the skin. During a stress test, the exercise or medication may trigger heart distress - not the ECG.

What to Expect Before the ECG

No preparation is required. However, avoid exercising immediately before an electrocardiogram. Physical activity, such as climbing stairs, may increase your heart rate.

What to Expect During the ECG

A standard ECG takes only few minutes and can be done in either the doctor's office or hospital. You will lie on an examination table. Various electrodes, often 12 to 15, will be attached to your arms, legs and chest. The electrodes are sticky patches applied with a gel. The gel helps detect and conduct the electrical currents of your heart.

You can breathe normally during the electrocardiogram. Make sure you are warm and ready to lie still. Moving, talking or shivering may distort the test results.

What to Expect After the ECG

If your electrocardiogram is normal, no further testing is needed. Your doctor may need a repeat ECG or other diagnostic tests if the results are inconclusive or concerning. Treatment depends on what is causing your signs and symptoms.


No follow-up is necessary after an electrocardiogram.