A Holter monitor is a type of heart monitor that records your heart’s activity over 24 or 48 hours. If you have an irregular heartbeat or heart palpitations, but an EKG didn’t detect anything, a cardiac monitor can help diagnose the problem. You wear the Holter monitor while you do your daily activities. Your provider discusses the results with you.
A Holter monitor is a wearable device and type of ambulatory electrocardiogram that records your heart’s rhythm and rate activity. It gives your provider a full picture of what your heart rhythm and rate does as you go about your life.
This monitor is:
A Holter monitor records your heart’s electrical activity for 24 or 48 hours. While you wear it, you continue to do your regular daily activities. The Holter monitor is named for Dr. Norman J. Holter, who created it in the 1950s.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
No, wearing a Holter monitor isn’t painful.
You may need a Holter monitor if you have an inconclusive electrocardiogram (ECG or EKG), a type of heart test. An inconclusive EKG means it didn’t provide clear results.
Maybe you saw your doctor because of signs of a heart rhythm problem — like your heart is racing or fluttering. Or you had unexplained fainting.
Your provider decided to do an EKG to find the problem. But the EKG only records your heart for a short period. Heart symptoms don’t always happen while you’re in the provider’s office.
If the EKG doesn’t tell your provider what they need to know, a Holter monitor can help. It gathers more information about your heart’s activity. You wear it for a full day or two, giving it more chances to spot unusual activity.
A Holter monitor can find the cause of:
Your provider can also use a cardiac monitor to determine how well your:
If you need urgent treatment for heart symptoms, then a Holter monitor would not be appropriate. Providers don’t recommend a cardiac monitor if it delays urgent care. Providers also do not use a Holter monitor for routine screening if you don’t have symptoms.
An EKG measures your heart’s activity at that moment in time, as you’re having the test. But your heart’s rhythm and symptoms can change over the day.
Your provider may want to see how your heartbeat changes during the day as you do your regular activities. The heart monitor gives your provider a fuller picture of your heart rhythm.
A Holter monitor records your heart continuously for 24 or 48 hours. An event monitor is not continuous. It only records your heart’s activity when you feel symptoms and activate the monitor.
You don’t need to do anything special to prepare for a Holter monitor. The technician may need to shave your chest where they attach the electrodes.
A technician connects you to the heart monitor and provides instructions. Here’s what you can expect:
While wearing your cardiac monitor, don’t:
After the 24- or 48-hour period:
Your provider may recommend:
A Holter monitor has no risks or pain associated with it.
The electrodes attach to your chest with tape. The tape might cause some itchiness or irritation. Let your provider know if you have any allergies to tapes or adhesives.
Your provider will call you with the results within a week or two after the test. The results may show that the heart monitor detected a heart rhythm disorder (arrhythmia), such as:
Your provider will discuss the next steps with you. You may need heart rhythm medications or further testing.
If your provider recommends a Holter monitor, ask:
A note from Cleveland Clinic
A Holter monitor provides a picture of your heart’s activity over 24 or 48 hours. It can help your provider diagnose the cause of a heart issue that doesn’t show up on an EKG. You wear the Holter monitor while you go about your regular activities. It helps your provider figure out what’s causing your heart flutters, racing heart or dizziness. The test is painless. After you finish the test, your provider discusses the results and next steps. You may need further testing or medication.
Last reviewed by a Cleveland Clinic medical professional on 04/12/2021.
Learn more about our editorial process.