This common, painless test can detect heart attacks and heart rhythm problems. Know when and why an ECG is done.
An electrocardiogram records the electrical signals in the heart. It's a common and painless test used to quickly detect heart problems and monitor the heart's health.
An electrocardiogram — also called ECG or EKG — is often done in a health care provider's office, a clinic or a hospital room. ECG machines are standard equipment in operating rooms and ambulances. Some personal devices, such as smartwatches, offer ECG monitoring. Ask your health care provider if this is an option for you.
An electrocardiogram (ECG or EKG) records the electrical signal from the heart to check for different heart conditions. Electrodes are placed on the chest to record the heart's electrical signals, which cause the heart to beat. The signals are shown as waves on an attached computer monitor or printer.
An electrocardiogram is a painless, noninvasive way to help diagnose many common heart problems. A health care provider might use an electrocardiogram to determine or detect:
You may need an ECG if you have any of the following signs and symptoms:
The American Heart Association doesn't recommend using electrocardiograms to assess adults at low risk who don't have symptoms. But if you have a family history of heart disease, your health care provider might suggest an electrocardiogram as a screening test, even if you have no symptoms.
If symptoms tend to come and go, they may not be detected during a standard ECG recording. A health care provider might recommend remote or continuous ECG monitoring. There are several different types.
An electrocardiogram is a safe procedure. There is no risk of electrical shock during the test because the electrodes used do not produce electricity. The electrodes only record the electrical activity of the heart.
You may have minor discomfort, similar to removing a bandage, when the electrodes are removed. Some people develop a slight rash where the patches were placed.
No special preparations are necessary for a standard electrocardiogram. Tell your health care provider about any medications and supplements you take. These can often affect the results of an ECG.
An electrocardiogram can be done in a health care provider's office or hospital.
You may be asked to change into a hospital gown. If you have hair on the parts of your body where the electrodes will be placed, the care provider may shave the hair so that the patches stick.
Once you're ready, you'll typically be asked to lie on an examining table or bed.
During an ECG, up to 12 sensors (electrodes) are attached to the chest and limbs. The electrodes are sticky patches with wires that connect to a monitor. They record the electrical signals that make the heart beat. A computer records the information and displays it as waves on a monitor or on paper.
You can breathe during the test, but you will need to lie still. Make sure you're warm and ready to lie still. Moving, talking or shivering may interfere with the test results. A standard ECG takes a few minutes.
You can typically return to your usual activities after your electrocardiogram.
Your health care provider might discuss results with you the same day as your electrocardiogram or at your next appointment.
ECG results can give a health care provider details about the following:
If results show a heart rhythm problem, you may need another ECG or other test, such as an echocardiogram. Treatment depends on what's causing your signs and symptoms.