Electrocardiogram

What Is an Electrocardiogram?

An electrocardiogram (ECG or EKG) is a quick, noninvasive test that records the electrical activity of the heart. Each heartbeat is triggered by electrical signals that travel through the heart muscle. An ECG measures these signals and displays them as waveforms, allowing healthcare providers to assess heart rhythm and detect abnormalities.

The test is safe, painless, and commonly performed in clinics, hospitals, and outpatient settings. It does not use radiation and typically takes only a few minutes to complete.

Why an Electrocardiogram Is Performed?

An ECG may be ordered to evaluate symptoms such as chest pain, palpitations, shortness of breath, dizziness, or fainting. It is also used during routine checkups, before surgery, or to monitor known heart conditions.

Common reasons for an ECG include detecting abnormal heart rhythms (arrhythmias), signs of a previous or current heart attack, problems with the heart’s electrical conduction system, or effects of medications on the heart. An ECG can also help assess conditions such as enlarged heart chambers or electrolyte imbalances.

What to Expect During the Test

During an electrocardiogram, you will lie flat on an exam table. A technician will place small adhesive electrodes on your chest, arms, and legs. These electrodes are connected to the ECG machine, which records your heart’s electrical signals.

You will be asked to lie still and breathe normally while the recording is made. The test itself takes only a few seconds, though setup may take several minutes. The electrodes are then removed, and you can return to your normal activities right away.

Results and Interpretation

The ECG tracing shows the timing and pattern of electrical activity in the heart. A healthcare provider reviews the results to look for irregular heart rhythms, slowed or fast heart rates, or changes that suggest heart muscle injury or strain.

A normal ECG does not always rule out heart disease, especially if symptoms come and go. Your provider will interpret the results in the context of your symptoms, medical history, and other tests, and will discuss whether further evaluation is needed.

Risks and Safety

An electrocardiogram is safe and has no known risks. The electrodes do not deliver electricity into the body; they only record the heart’s natural electrical activity. Some patients may experience mild skin irritation where the electrodes were placed, but this is usually temporary.

If you have questions about your electrocardiogram or your results, talk with your healthcare provider. They can explain what the test shows and how it fits into your overall care plan.