A Holter monitor is a battery-operated portable device that records your heart’s activity for 24 to 48 hours. You wear it while you go about your normal activities. The monitor checks your heart’s electrical activity, called an electrocardiogram (ECG or EKG).
The Holter monitor is about the size of a deck of cards and is worn in a pouch around your neck or waist. It’s connected to your chest by thin wires that are taped in place. You’ll also have a small recorder that you carry with you to record your heart’s activity.
At the end of the recording period, you’ll return the monitor and recorder to your doctor or a technician, who will download the information from the recorder and analyze it. The analysis can help your doctor find out if you have a heart condition and, if so, what type it is.
In some cases, you may need to wear the Holter monitor for a second recording period to get more information about your condition. Or your doctor may recommend that you have a different type of heart test.
Why you might need a Holter monitor
Your doctor may recommend a Holter monitor if you have signs or symptoms of a heart condition, such as:
- An irregular heartbeat (arrhythmia)
- Palpitations the sensation that your heart is skipping a beat or beating too hard or fast
- Fainting (syncope)
- Shortness of breath
A Holter monitor can also be used to check the effectiveness of treatments for a heart condition.
How to prepare for a Holter monitor test
To prepare for a Holter monitor test:
- Wash your skin where the monitor will be attached. Be sure to remove any oils, lotions, or makeup from your skin.
- Don’t drink caffeinated beverages for 24 hours before the test. Caffeine can affect your heart rate.
- Make a list of all the medications you’re taking, including over-the-counter drugs and supplements. Your doctor will need to know if you’re taking any heart medications, such as beta blockers.
- Ask your doctor if you should stop taking any medications before the test.
- Wear comfortable clothing that doesn’t restrict your movement. You’ll need to remove your shirt so the monitor can be attached to your chest.
What you can expect during a Holter monitor test
During a Holter monitor test:
- You’ll be asked to remove your shirt so the monitor can be attached to your chest. The monitor has sticky pads (electrodes) that are placed on your skin. The electrodes are connected to the monitor by wires.
- The monitor and electrodes are held in place by an adhesive patch or tape. You’ll also be given a small recorder to carry with you. The recorder is connected to the monitor by a wire.
- You’ll be asked to keep a diary of your activities during the recording period. You’ll also be asked to note any symptoms you experience, such as dizziness or shortness of breath.
- At the end of the recording period, you’ll return the monitor and recorder to your doctor or a technician, who will download the information from the recorder and analyze it.
How to remove a Holter monitor
To remove a Holter monitor:
- Wash your hands with soap and water.
- Gently remove the electrodes from your skin. If the electrodes are stuck to your skin, wet them with warm water to loosen the adhesive.
- Remove the monitor from your body.
- Remove the recorder from your body.
- Disconnect the monitor from the recorder.
- Place the monitor and recorder in the shipping box or bag that was provided.
- Seal the box or bag.
- Call the company that supplied the monitor to arrange for shipping.
After a Holter monitor test
After a Holter monitor test:
- You can return to your normal activities.
- If you have any skin irritation from the electrodes, apply a soothing lotion to the affected area.
Your doctor will review the results of your Holter monitor test and let you know if any further testing or treatment is needed.