Heart Disease and Electrocardiograms

Medically Reviewed by James Beckerman, MD, FACC on June 30, 2023
3 min read

Your doctor may suggest you get an electrocardiogramalso called an EKG or ECGto check for signs of heart disease. It's a test that records the electrical activity of your heart through small electrode patches that a technician attaches to the skin of your chest, arms, and legs.

EKGs are quick, safe, and painless. With this test, your doctor will be able to:

  • Check your heart rhythm
  • See if you have poor blood flow to your heart muscle (this is called ischemia)
  • Diagnose a heart attack
  • Check on things that are abnormal, such as thickened heart muscle
  • Detect if there are significant electrolyte abnormalities, such as high potassium or high or low calcium.

Some things you can do to get yourself ready:

  • Avoid oily or greasy skin creams and lotions on the day of the test because they can keep the electrodes from making contact with your skin.
  • Avoid full-length hosiery because electrodes need to be placed directly on your legs.
  • Wear a shirt that you can remove easily to place the leads on your chest.

A technician will attach 10 electrodes with adhesive pads to the skin of your chest, arms, and legs. If you're a guy, you may need to shave your chest hair to allow a better connection.

During the test, you'll lie flat while a computer creates a picture, on a graph paper, of the electrical impulses that move through your heart. This is called a "resting" EKG although the same test may be used to check your heart while you exercise.

It takes about 10 minutes to attach the electrodes and complete the test, but the actual recording takes only a few seconds.

Your doctor will keep your EKG patterns on a file so that they can compare them to tests you get in the future.

Besides the standard EKG, your doctor may recommend other types:

Holter monitor. It's a portable EKG that checks the electrical activity of your heart for 1 to 2 days, 24 hours a day. Your doctor may suggest it if they suspect you have an abnormal heart rhythm, you have palpitations, or you don't have enough blood flow to your heart muscle.

Like the standard EKG, it's painless. The electrodes from the monitor are taped to your skin. Once they're in place, you can go home and do all of your normal activities, except take a shower. Your doctor will ask you to keep a diary of what you did and any symptoms you notice.

Event monitor. Your doctor may suggest this device if you only get symptoms now and then. When you push a button, it will record and store your heart's electrical activity for a few minutes. You may need to wear it for weeks or sometimes months.

Each time you notice symptoms, you should try to get a reading on the monitor. The info is sent on the phone to your doctor who will analyze it.

Signal-averaged EKG. This is a painless test used to assess whether a person is at high risk of developing a potentially fatal heart arrhythmia. It is performed in a similar manner to the EKG but uses sophisticated technology to look for risk for heart arrhythmias.

Abnormal EKG results could be a sign of a number of conditions including:

  • Atrial fibrillation/flutter
  • Heart attack (current or past)
  • Heart failure
  • Genetic heart defects
  • Abnormal heart rhythms (arrhythmias)
  • Sick sinus syndrome
  • Wolff-Parkinson-White syndrome
  • Poor blood supply to heart
  • Heart enlargement
  • Swelling or extra fluid in the sac around the heart
  • Heart inflammation (myocarditis)

Show Sources


MedlinePlus: "Electrocardiogram" and "Holter Monitor (24h)."

American College of Cardiology -- CardioSmart.org: "Women and Heart Disease."

American Heart Association

View privacy policy, copyright and trust info