Your doctor might order this 24-hour monitor to help better assess your heart health. This could help them make any changes to medication or other heart-related habits or possibly order additional testing.

A Holter monitor is a small, battery-powered medical device that measures your heart’s activity, such as rate and rhythm.

While you wear the Holter monitor for 12 to 48 hours as you go about your regular daily routine, this device monitors your heart rate and rhythm for 24 hours.

The device uses electrodes and electrical leads like a routine electrocardiogram (EKG) but has fewer leads. It can detect not only your heart rate and rhythm but also when you feel chest pains or exhibit symptoms of an irregular heartbeat or arrhythmia.

Your doctor may ask you to use one if they need more information about how your heart functions than a routine EKG can give them.

What is a Holter monitor used for?

Abnormal heart rhythms and other types of cardiac symptoms can come and go.

Also called ambulatory electrocardiography, a Holter monitor lets your doctor see how your heart functions over the course of a day. The recordings made by the monitor can help your doctor determine if your heart is getting enough oxygen or if the electrical impulses in the heart are delayed or early. These irregular impulses may be referred to as arrhythmias or abnormal heart rhythms.

If you’re already being treated for heart problems, wearing your monitor can help your doctor determine if your medication is working or if changes need to be made. This can also help determine if you need a longer-term analysis on your heart.

It can also help your healthcare team determine why you might be experiencing other symptoms of irregular heartbeat, including dizziness, faintness, or feeling like your heart is racing or skipping a beat.

How it works

The Holter monitor is small, 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, where it’s recorded.

  • 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 ensure accurate readings.
  • Your doctor will show you how to reattach electrodes if they become loose or fall off during the testing period.
  • You’ll receive instructions that explain how to care for 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 24-hour Holter test.
  • You’ll be directed to record your activities in a notebook. This can help your doctor determine whether changes in heart activity are related to your behaviors and movements.

Are there possible risks from the Holter monitor?

Wearing the Holter monitor itself poses no risks.

However, the tape or adhesives that attach the electrodes to your skin may cause mild skin irritation in some people. If you’re allergic to any tapes or adhesives, make sure to tell the technician who attaches your monitor.

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.

Tips on proper wear and Holter monitor accuracy

In an event where misreadings or false positives do occur, the Holter may need to be applied again.

You can take these steps to help ensure it’s properly worn and you get accurate results:

  • Keep the Holter monitor dry to ensure it functions properly.
  • Take a bath or shower before your appointment to have the monitor fitted.
  • Don’t apply lotions or creams.
  • Avoid activities that might cause the monitor to get wet.
  • Magnetic and electrical fields may interfere with the Holter monitor’s function. So, 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 monitor’s results.

Depending on the test results, you may need to undergo further testing before a diagnosis is made.

The Holter monitor may reveal that your medication isn’t working or your dosage needs to be altered if you’re already taking medication for an abnormal heart rhythm. It’s especially useful in detecting abnormal heart rhythms that are painless and unknown to you.

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

The takeaway

A Holter monitor can help your doctor better understand your heart health and any abnormalities in your heart rate and rhythm.

This is one type of heart health, similar in many ways to a routine EKG. You might also need other tests to monitor your health for longer periods of time.

The Holter monitor may help determine if your medications or other heart-related care needs adjusting, or if more testing might be needed for heart disease or other possible medical conditions.