24-Hour Holter Monitoring

What Is a Holter Monitor?


  1. A Holter monitor is a device commonly used to keep track of your heart rhythm.
  2. Your doctor can use a Holter monitor to keep track of your heart function if you’re having heart problems or they think there may be a problem.
  3. Make sure to engage in your normal activities and keep the Holter monitor dry while your heart is being monitored. Your doctor will remove the monitor when testing is finished and carefully go over your results to determine the next step.

A Holter monitor is a small, battery-powered medical device that measures your heart’s activity, such as rate and rhythm. Your doctor may ask you to use one if they need more information about how your heart functions than a routine electrocardiogram (EKG) can give them.

Twenty-four hour Holter monitoring is a continuous test to record your heart’s rate and rhythm for 24 hours. You wear the Holter monitor for 12 to 48 hours as you go about your normal daily routine. This device has electrodes and electrical leads exactly like a regular EKG, but it has fewer leads. It can pick up not only your heart’s rate and rhythm but also when you feel chest pains or exhibit symptoms of an irregular heartbeat, or arrhythmia.

Holter monitor testing is also sometimes called ambulatory electrocardiography.

Uses for Holter Monitoring


An EKG is a medical test that’s used to measure your heart rate and rhythm. It’s also used to look for other abnormalities that may affect normal heart function. During an EKG, electrodes are placed on your chest to check your heart’s rhythm. You may experience heart rhythm irregularities that don’t show up at the time the EKG is done because you’re only hooked up to the machine for a very brief amount of time.

Abnormal heart rhythms and other types of cardiac symptoms can come and go. Monitoring for a longer period of time is necessary. The Holter monitor lets your doctor see how your heart functions on a long-term basis. The recordings made by the monitor help your doctor determine if your heart is getting enough oxygen or if the electrical impulses in the heart are delayed.

If you’re already being treated for heart problems, wearing your monitor can help your doctor determine if your medicine is working or if changes need to be made. It can also help them to see why you might be experiencing other symptoms of irregular heartbeat, such as dizziness, faintness, or feeling like your heart is racing or skipping a beat.

How It Works


The Holter monitor is small. It’s slightly larger than a deck of playing cards. Several leads, or wires, are attached to the monitor. The leads connect to electrodes that are placed on the skin of your chest with a glue-like gel. The metal electrodes conduct your heart’s activity through the wires and into the Holter monitor.

You wear a small pouch around your neck that holds the monitor itself. It’s important to keep the monitor close to your body during the testing period to make sure the readings are accurate. Your doctor will show you how to reattach electrodes if they become loose or fall off during the testing period.

You’ll get instructions that explain how to take care of your monitor and what not to do while you’re wearing it. It’s important to avoid bathing, showering, and swimming while you’re wearing the monitor.

You’re encouraged to participate in your normal activities during the Holter 24-hour test. You’ll be directed to record your activities in a notebook. This helps your doctor determine if changes in heart activity are related to your behaviors and movements.

Wearing the Holter monitor itself has no risks involved. However, the tape or adhesives that attach the electrodes to your skin can cause mild skin irritation in some people. Make sure to tell the technician that attaches your monitor if you’re allergic to any tapes or adhesives.

A 24-hour Holter monitor test is painless. However, be sure to record any chest pain, rapid heartbeat, or other cardiac symptoms you have during the testing period.

Accuracy of Testing

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Keep the Holter monitor dry to ensure it functions properly. Take a bath or shower before your appointment to have the monitor fitted and don’t apply any lotions or creams. Avoid activities that might lead to the monitor getting wet.

Magnetic and electrical fields may interfere with the function of the Holter monitor. Avoid areas of high voltage while wearing the monitor.

Understanding the Results


After the recommended testing time frame has passed, you’ll return to your doctor’s office to have the Holter monitor removed. Your doctor will read your activity journal and analyze the results of the monitor. Depending on the results of the test, you may need to undergo further testing before a diagnosis is made.

The Holter monitor may reveal that your medicine isn’t working or your dosage needs to be altered if you’re already taking medication for an abnormal heart rhythm.

Wearing a Holter monitor is painless and one of the best ways to identify potential heart problems or other issues.

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