What Is an Electrocardiogram?

An electrocardiogram, also called an EKG or ECG, is a simple test that measures electrical impulses in your heart. Every time your heart beats, an electrical wave flows through it, causing your heart to squeeze and pump blood through your body. An EKG can let your doctor know if your heart is beating normally and measure your heart’s chambers.

Why Would Your Doctor Order an Electrocardiogram?

If you have signs of a heart problem, your doctor might order an EKG. Symptoms include:

  • palpitations or irregular heartbeat or rapid heartbeat
  • chest pain
  • dizziness
  • shortness of breath
  • unusual tiredness

Your doctor might also do an EKG if you have:

  • a family history of heart disease
  • a heart attack or other heart issues in the past
  • medication for a cardiac condition
  • a pacemaker to regulate your heartbeat
  • upcoming surgery

What to Expect During an Electrocardiogram

An EKG is painless. You will lie on an exam table, where a nurse or technician will place adhesive electrodes on your chest, arms and legs. He or she might need to shave these spots before attaching the electrodes. Wires attached to the electrodes are connected to a computer that displays your heart’s electrical activity. Your provider might also print out results. The entire procedure takes less than five minutes.

What Does an Electrocardiogram Show?

Your doctor looks for two important pieces of information from your EKG. First, by seeing how long it takes for electrical impulses to travel through your heart’s chambers, your doctor can tell if your heart is beating in a regular rhythm. Second, the amount of electrical activity in your heart can reveal if the chambers are too large or if they seem to be working too hard.

This information can help your doctor diagnose:

  • cardiomyopathy, a thickening or enlargement of the heart muscle
  • a heart arrhythmia, or a problem with the rhythm of your heartbeat
  • a heart attack
  • a heart failure
  • heart valve disease
  • insufficient blood flow to the heart
  • pericarditis, a swelling of the sac around your heart

What to Expect After an Electrocardiogram

Based on EKG results, your doctor may recommend further diagnostic testing for your heart. An abnormal EKG is not always cause for concern. Remember that an EKG does not show all heart conditions. If you have other symptoms that concern you, talk to your doctor.