What Is Holter Monitoring?

Holter monitoring is a painless way to record your heartbeat away from your healthcare provider’s office. It's a small, battery-operated, portable electrocardiogram (ECG) machine. It has wires that are put on your chest and a device to carry with you. It's about the size of a small digital camera. Holter monitoring records your heartbeat for at least 24 hours. Your provider then reviews the information at a later time. You can get your Holter monitor at a hospital, test center, or provider’s office.

The monitor is used to record any problems with your heartbeat. It can show racing heartbeats, slow heartbeats, skipping heartbeats, fluttering heartbeats (palpitations), and fainting. All of these symptoms may be caused by an irregular heartbeat (arrhythmia). Holter monitors also provide information about your average heart rate throughout the day.

Man's torso showing five ECG leads attached to chest and connected to Holter monitor clipped to belt.

Your Holter monitor

When you get a Holter monitor, your healthcare provider puts small, sticky pads (electrodes) on your chest. These connect to the monitor. The monitor attaches to a belt or shoulder strap. Newer Holter monitors don't require wires or leads. They're placed directly over the heart with a sticky patch. You need to keep the device on for at least 24 to 48 hours, or as directed by your provider. You also need to fill out a diary keeping track of any symptoms you may have during the monitoring period. Your provider will tell you how to do this.

While wearing the monitor, follow these tips:

  • Try to sleep on your back.

  • Don’t take a shower. A sponge bath is OK.

  • Follow your normal routine. Go to work and exercise as usual. It's important to record your heartbeat during your normal activities.

  • If an electrode falls off or the unit makes noise, call your healthcare provider. Or call the phone number for device support to see what you should do.

  • When the monitoring period is over, you will return to your provider's office or an electrocardiogram center. Sometimes your monitor may be returned by mail. Make sure you know where to return your device. Once your provider receives the information from your monitor, it will be reviewed.

  • It may take about 1 week for the information to be looked at. Ask your provider if you should have a follow-up appointment or how you will get the results from your test.

When using a Holter monitor...

While wearing the monitor, stay away from things that may affect the recording, such as:

  • Electric blankets

  • Magnets

  • Metal detectors

  • High-voltage areas such as power lines


And don’t use machines with large motors or that cause vibrations. These can also affect the recording.

Keeping a Holter monitor diary

Keep a diary of things you do during the day. This is important. It could help you match your symptoms to times when your heart is beating abnormally.

  • Write down when you take medicines, drive to work, take a nap, or feel stress.

  • Record the time of day for each entry you make.

  • Note any changes in activity, including when you take medicines.

  • Note any symptoms you feel. These might be fluttering heartbeats or skipped beats.

Sample Holter monitor diary

Call 911

Call 911 right away if any of these occur:

  • Dizziness or lightheadedness

  • Chest pain or pressure

  • Shortness of breath

  • Strong fluttering heartbeats

Online Medical Reviewer: Anne Clayton APRN
Online Medical Reviewer: Stacey Wojcik MBA BSN RN
Online Medical Reviewer: Steven Kang MD
Date Last Reviewed: 10/1/2021
© 2000-2022 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.