A Holter monitor is a device that continuously records your heart’s activity for a short period of time, usually 24 to 48 hours. It works as a portable electrocardiogram (EKG) that measures your heart’s electrical activity. Unlike a traditional EKG that takes only a few seconds worth of data, a Holter monitor gives your doctor more detailed information about your heart during normal activity. As you wear the monitor, it measures the speed and regularity of your heartbeat and the strength and timing of your heart’s electrical impulses.
Why Do You Need a Holter Monitor?
Holter monitors help doctors diagnose arrhythmia (irregular heartbeat) and determine the success of treatments. You may be asked to wear a Holter monitor if you:
- Become faint or dizzy regularly
- Experience irregular heartbeat
- Need to determine whether your heart is getting enough oxygen
- Recently had a heart attack
- Take medications intended to treat a cardiac condition
Getting Ready for a Holter Monitor
Holter monitors generally have small electrodes that attach directly to your chest with adhesive. Wires connect these electrodes to a monitor that you keep in a pocket, hang over your shoulder or wear around your waist. Very little preparation is needed before you wear one. However, you cannot get the electrodes or monitor wet, so you should bathe or shower prior to receiving the device. Men who have hair on their chests may need to shave the area where the electrodes will be placed.
Electricity and magnets can affect the Holter monitor’s readings, so you will need to take some precautionary steps:
- Avoid electric blankets, electric razors, electric toothbrushes, magnets, metal detectors and microwave ovens while wearing the device.
- Do not have any X-rays while wearing your monitor.
- Keep cellphones and other electronic devices, such as MP3 players and tablets, away from the monitor.
What to Expect During a Holter Monitor Test
Wearing a Holter monitor is painless, and you will be free to go about your usual activities. However, you will need to track any symptoms, such as dizziness or unusual heartbeat, in a diary. Note the time and what you were doing when the symptoms occurred.
When your test period is complete, you will return your Holter monitor to your healthcare provider. He or she will then process your test results, which should be ready for you within one to two weeks.
