An electrocardiogram (ECG) is a medical test that detects cardiac (heart) abnormalities by measuring the electrical activity generated by the heart as it contracts. The machine that records the patient’s ECG is called an electrocardiograph.
EKGs/ECGs 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.
How Should I Prepare?
Some things you can do to get yourself ready:
- Avoid oily or greasy skin creams and lotions 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.
What Happens During an Electrocardiogram?
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 have your chest hair shaved to allow a better connection.
During the test you’ll lie flat while a computer creates a picture, on 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 file so that they can compare them to tests you get in the future.