An electrocardiogram (e-lek-tro-KAR-de-o-gram), also called an EKG or ECG, is a simple, painless test that records the heart’s electrical activity. To understand this test, it helps to understand how the heart works.
With each heartbeat, an electrical signal spreads from the top of the heart to the bottom. As it travels, the signal causes the heart to contract and pump blood. The process repeats with each new heartbeat.
The heart’s electrical signals set the rhythm of the heartbeat.
An EKG shows:
•How fast your heart is beating
•Whether the rhythm of your heartbeat is steady or irregular
•The strength and timing of electrical signals as they pass through each part of your heart
Doctors use EKGs to detect and study many heart problems, such as heart attacks, arrhythmias (ah-RITH-me-ahs), and heart failure. The test’s results also can suggest other disorders that affect heart function.
Who Needs an Electrocardiogram?
Your doctor may recommend an electrocardiogram (EKG) if you have signs or symptoms that suggest a heart problem. Examples of such signs and symptoms include:
•Heart pounding, racing, or fluttering, or the sense that your heart is beating unevenly
•Tiredness and weakness
•Unusual heart sounds when your doctor listens to your heartbeat
•You may need to have more than one EKG so your doctor can diagnose certain heart conditions.
An EKG also may be done as part of a routine health exam. The test can screen for early heart disease that has no symptoms. Your doctor is more likely to look for early heart disease if your mother, father, brother, or sister had heart disease—especially early in life.
You may have an EKG so your doctor can check how well heart medicine or a medical device, such as a pacemaker, is working. The test also may be used for routine screening before major surgery.
Your doctor also may use EKG results to help plan your treatment for a heart condition.
What To Expect During an Electrocardiogram
An electrocardiogram (EKG) is painless and harmless. A nurse or technician will attach soft, sticky patches called electrodes to the skin of your chest, arms, and legs. The patches are about the size of a quarter.
Often, 12 patches are attached to your body. This helps detect your heart’s electrical activity from many areas at the same time. The nurse may have to shave areas of your skin to help the patches stick.
After the patches are placed on your skin, you’ll lie still on a table while the patches detect your heart’s electrical signals. A machine will record these signals on graph paper or display them on a screen.
The entire test will take about 10 minutes.