Cardiac Event Monitor

A cardiac event monitor can provide valuable information ― just like an EKG ― to help your provider diagnose your heart issue. Wearing a monitor for a few weeks helps you record symptoms that don’t happen every day. Different kinds of cardiac event recorders are available, but whichever type you use has to be with you all the time.


Cardiac event monitor placement to record heart activity.
Cardiac event monitor tracks heart rate and rhythm

What is a cardiac event monitor?

A cardiac event monitor is a small piece of equipment you wear or carry that records your heart rate and heart rhythm for your provider to review. These devices can collect the same information as an electrocardiogram (EKG), but they’re smaller than a deck of cards. Since you can have this battery-powered device with you for up to a month, it’s good for recording abnormal heart rhythms that don’t happen every day.

Types of cardiac event monitors

  • Patch recorder: This is good for two weeks and has everything contained in one unit (patch) you wear on your chest.
  • Symptom event monitor: You put the sensors on and turn the device on when you have symptoms.
  • Loop memory monitor: You keep the sensors on and start the device when you have symptoms. It can record your EKG while symptoms are happening, but also a minute or two before and after they start.
  • Implanted loop recorders: This multi-year option is the only type that goes under your skin.

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

When is a cardiac event monitor used?

Your healthcare provider will ask you to use a cardiac event recorder if you’re having symptoms that don’t happen that often ― like once a week or once a month. When your car is making a sound that concerns you, it might not make that sound when you take it to the mechanic. In a similar way, your heart may not have an abnormal rhythm during your appointment with your provider. Having a device that records your heart’s rhythm allows your provider to review the recording and make a diagnosis.

Reasons to use a cardiac event monitor

Your provider can use the information from a cardiac event recorder when:

Cardiac event monitor vs. Holter monitor

If you’re having frequent symptoms, your provider will ask you to use a Holter monitor, which is a device that records your heart rhythm continuously for 24 to 48 hours. If your provider gets enough information from the Holter monitor to diagnose you, you won’t need to try a cardiac event monitor. If you’ve tried the Holter monitor but it hasn’t given your provider enough information for a diagnosis, you may need to use a cardiac event monitor.

Who prescribes a cardiac event monitor?

Your cardiologist, a healthcare provider who specializes in the heart, will ask you to use a cardiac event monitor. They’ll review the information it gathers and make a diagnosis from that.


Test Details

How does a cardiac event monitor work?

Sensors on your chest will pick up your heart rhythms and send them through wires (or wirelessly) to your cardiac event monitor, which will record them. You’ll send this information to your healthcare provider through the phone or a computer so they can review it and look for any abnormal heart rhythms. If they see an arrhythmia that’s a concern, they may call you and ask you what symptoms you’re having. They may also ask you to come in for a checkup so they can evaluate you.

What to expect on the day you get a cardiac event monitor

Your provider will use sticky strips of plastic to attach several sensors to the skin on your chest. (Be sure to let them know if you’re allergic to the adhesive they’re using.) They’ll shave chest hair that’s in the way of where a sensor will go and use alcohol to clean and prepare your skin for the sensors. The plastic strips won’t stay on if your skin is oily or sweaty.

Although you can wear the sensors in the shower or bathtub, you’ll get a supply of sensors so you can switch them out with new ones. Your provider will tell you how often to replace them and where they should go.

For some cardiac event monitors, you don’t need to stick sensors on your chest. You just wear the monitor on one of your wrists or hold it up to your chest. For some cardiac event monitoring devices, you’ll need to push a button to record your heart rhythm when you’re having symptoms. Others will start recording on their own when an abnormal heart rhythm happens.


What to expect when using a cardiac event monitor

You’ll need to wear or carry a device that receives information from the sensors attached to your body. Depending on the type of cardiac event recorder, you might carry it with you in your hand or pocket or wear it on one of your wrists.

Follow your provider’s instructions. They may want you to exercise so they can see what your EKG records for that time frame. Otherwise, just do what you normally do. It’s helpful to keep track of what you’re doing and any symptoms you’re having when you’re active. You should also make note of when you took heart medications.

Things that may keep the sensors from communicating with the cardiac event monitor

You may need to avoid or keep your monitor a safe distance from these:

  • Electric blankets, toothbrushes and razors.
  • Magnets.
  • Cell phones.
  • Portable music (MP3) players.
  • Microwave ovens.
  • Computer tablets.
  • Metal detectors.
  • Places with high voltage.

What should I expect after using a cardiac event monitor?

After your healthcare provider has the information they need from your cardiac event monitor, you’ll return it to them. If you had an implantable type of cardiac event recorder, your provider will take it out. In the case of a patch, you may need to mail it when you’re done with it.

What are the risks of a cardiac event monitor?

The adhesive on the sensor patches may irritate your skin, but that goes away when you take off the patches. For the implanted type of cardiac event recorder, you may have a small risk of pain or infection from the procedure to put the device under your skin.

Using a cardiac event monitor is painless. You’ll just be aware of the sensors attached to your skin.

Results and Follow-Up

What type of results do you get and what do the results mean?

A cardiac event monitor can give your provider information that answers questions such as:

  • Does your heart have a steady rhythm?
  • How strong are your heart’s electrical signals?
  • Do your heart’s electrical signals have normal timing?
  • How fast is your heart beating?

If your healthcare provider doesn’t see any major changes in your heart rhythms, your results are normal. If your cardiac event monitor results show abnormal heart rhythms, you may have an arrhythmia such as:

After getting your cardiac event monitor results, your provider may want to do more testing or move forward with treatment.

When should I know the results of a cardiac event monitor?

Depending on the type of cardiac event recorder you have, it may take a few days or a week or two to get results. Ask your provider when you can expect to get results.

When should I call my doctor?

Call your healthcare provider if you have questions about using your cardiac event monitor or if any cardiac event monitor instructions they gave you aren’t clear.

Call 911 if you think you’re having a heart attack.

A note from Cleveland Clinic

While it may be inconvenient to wear a cardiac event monitor, it will give your healthcare provider the information they need to understand what your heart is doing. Once they know what’s happening with your heart, they can make a diagnosis and give you the treatment you need. The temporary inconvenience is worth it to get long-term relief from your symptoms.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 06/11/2022.

Learn more about our editorial process.

Appointments 800.659.7822