Electrocardiogram (ECG or EKG)

An electrocardiogram (ECG or EKG) is a simple and fast outpatient diagnostic procedure used to evaluate the electrical system of the heart.

UPMC cardiologists are experts at using the latest in EKG technology to diagnose and monitor a range of heart conditions and abnormal heart rhythms.

What Is an Electrocardiogram?

An electrocardiogram (ECG or EKG) is a simple and fast outpatient diagnostic procedure used to evaluate your heart's electrical system.

During an ECG, electrodes (small, plastic patches) are placed at certain locations on the chest, arms, and legs. When the electrodes are connected to an ECG machine by lead wires, the electrical activity of the heart is measured, interpreted, and printed out to help your doctor diagnose your heart condition.

The cardiologists at UPMC have years of experience using ECGs to diagnose heart arrhythmias and determine appropriate treatments.

What is the difference between an EKG and an electrocardiogram?

EKG is an abbreviation for an electrocardiogram and refers to the same procedure.

What does an EKG measure?

The heart is a pump made of muscle tissue. Its pumping action is regulated by an electrical conduction system that coordinates the contraction of the various chambers of the heart.

An electrocardiogram measures the heart's electrical activity. By placing electrodes at specific locations on the body (chest, arms, and legs), a graphic representation, or tracing, of the electrical activity can be obtained. Changes in an ECG from a normal tracing may indicate one or more of several heart-related conditions.

When the doctor views an ECG, he or she studies the size and length of each part of the ECG. Variations in size and length of the different parts of the tracing may be significant.

Conditions we diagnose with EKG

• Atrial fibrillation (AFib).
• Atrial flutter.
• Bradycardia.
• Tachycardia.
• Other abnormal heart rhythms, called arrhythmias.
• A previous heart attack.
• The cause of chest pain.

Why Would I Need an ECG?

Reasons your doctor may request an outpatient ECG include:

• Assessing the function of an implanted pacemaker.
• Determining the cause of chest pain.
• Determining the effectiveness of certain heart medications.
• Determining the status of the heart before or after heart surgery or cardiac catheterization.
• Determining the status of the heart before or after treatment for conditions such as a heart attack or endocarditis (inflammation or infection of one or more of the heart valves).
• Evaluating other signs and symptoms that may be heart-related, such as fatigue, shortness of breath, dizziness, or fainting.
• Identifying irregular heartbeats.
• Obtaining a baseline tracing of the heart’s function during a physical examination to be used as a comparison with future ECGs, to determine if any changes have occurred.

There may be other reasons for your doctor to recommend an ECG.

Who’s a candidate for ECG?

You may need an ECG if you have:

• A history or symptoms of an abnormal heart rhythm.
• A pacemaker or ICD.
• Chest pain.
• Signs of a previous heart attack.
• Symptoms such as dizziness, fatigue, shortness of breath, or fainting.

What Are the Risks and Complications of ECG?

An ECG is a quick, noninvasive method of assessing the heart's function. The risks associated with it are minimal and rare.

What Should I Expect During An ECG?

Before: How to prepare for an ECG

Your doctor or technician will explain the procedure to you and allow you to ask any questions that you might have.

• Based on your medical condition, your doctor may request another specific preparation.
• Generally, fasting is not required before the test.
• Notify your doctor of all medications (prescribed and over-the-counter) and herbal supplements that you are taking.
• Notify your doctor if you have a pacemaker.

How long does an EKG take?

An EKG is a simple, painless test that takes a few minutes to complete.

During your EKG

An ECG may be performed on an outpatient basis or as part of your stay in a hospital. Procedures may vary depending on your condition and your doctor's practices. Generally, an ECG follows this process:

• You will be asked to remove any jewelry or other objects that may interfere with the procedure.
• You will be asked to remove clothing from the waist up. The technician will ensure your privacy by covering you with a sheet or gown and exposing only the necessary skin.
• You will lie flat on a table or bed for the procedure. It will be important for you to lie still and not talk during the procedure, so as not to interfere with the tracing.
• If your chest, arms, or legs are very hairy, the technician may shave or clip small patches of hair, as needed, so that the electrodes will stick closely to the skin.
• Electrodes will be attached to your chest, arms, and legs.
• The lead wires will be attached to the skin electrodes.
• After the leads are attached, the technician may key in identifying information about you into the machine's computer.
• The ECG will be started. It will take only a short time for the tracing to be completed.
• After the tracing is completed, the technician will disconnect the leads and remove the electrodes from your skin.

Recovery after ECG

You should be able to resume your normal diet and activities unless your doctor instructs you differently. Generally, there is no special care following an ECG.

When to call your doctor about ECG complications

Notify your doctor if you develop any signs or symptoms you had prior to the test (for example, chest pain, shortness of breath, dizziness, or fainting).

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By UPMC Editorial Staff. Last reviewed on 2024-10-01.