Holter Monitoring: About This Test
What is it?
A Holter monitor is a small machine that you wear to record the electrical activity of your heart while you do your usual activities. Small electrode discs are taped to your chest. These discs are attached to wires that lead to the monitor. This test gives a 24- to 72-hour record of the electrical signals from your heart. It is also known as an ambulatory monitor, an ambulatory electrocardiogram, an ambulatory EKG, a 24-hour EKG, or a cardiac event monitor.
Why is this test done?
You may have this test to find out if you have a problem with your heart. Many heart problems are only noticeable during activity, such as exercise, eating, sex, stress, bowel movements, or even sleeping. A Holter monitor will record any changes to your heartbeat that happen during these activities.
Holter monitoring also will:
- Look for what might be causing chest pain, dizziness, or fainting.
- Look for poor blood flow to your heart muscle (ischemia).
- Check to see if treatment for an irregular heartbeat is working.
How can you prepare for the test?
- Talk to your doctor before the test about all your health conditions and all the medicines or vitamins you take.
- Take a shower or bath before the discs are put onto your chest. You will not be able to get the discs wet during the test.
- Wear a loose blouse or shirt.
- Do not wear jewelry or clothes with metal buttons or buckles.
- Women should not wear an underwire bra.
What happens before the test?
- Areas of your chest may be shaved and cleaned.
- The electrode discs will then be attached to the skin of your chest by a small amount of electrode paste or gel.
- You will wear the lightweight, battery-operated monitor on a strap over your shoulder or around your waist.
What happens during the test?
- You will be asked to keep a record of all your activities and symptoms, including the type of activity you were doing and the time your symptoms started.
- A clock is connected to the monitor so you can note the time when you have any symptoms.
- When you sleep, try to stay on your back with the monitor positioned at your side so that the discs are not pulled off.
What else should you know about the test?
- While you are wearing the monitor, try to stay away from magnets, metal detectors, high-voltage areas, garage door openers, microwave ovens, and electric blankets.
- Do not use an electric toothbrush or shaver.
- The disc sites may itch slightly during the monitoring period, and the skin on your chest may look or feel irritated when the discs are removed.
How long does the test take?
- You usually wear the monitor for 24 hours.
What happens after the test?
- After the monitoring period, you will return to the doctor's office or hospital to have the discs removed, or you may be able to remove them yourself.
- You can go back to your usual activities right away.