Loop Monitor

(Also called: Cardiac event recorder, patient-activated ECG)

A loop monitor is a non-invasive wearable device that can be used to record the electrical activity of your heart as you go about your daily routine. This information may be required in order to detect any heart rhythm abnormalities, to adjust medications, or to match symptoms with heart activity.

If you have signs and symptoms of an arrhythmia such as palpitations (episodes of rapid heartbeats) or unexplained fainting or dizziness that seem to come and go or only happen infrequently, your doctor may recommend wearing a loop monitor for two weeks.

The loop recorder only records your heart activity when you press the recording button. In some cases, the monitor itself can actually detect an abnormal rhythm and initiate a recording automatically. 

Over the two-week period, each time you feel your symptoms coming on, you press the record button. Each recording is analyzed according to the symptoms documented. A cardiologist reviews and summarizes the results and sends a report back to your doctor.


Your doctor must order a loop monitor test and fully complete a requisition form. Your doctor’s office will contact the Cardiac Diagnostic Centre to book the appointment and will contact you with the date and time. If you are given a requisition form, please bring it with you. A few days before your scheduled appointment, you will receive an automated phone call reminder of your appointment.

If you need to change the appointment date, you can contact the Cardiac Diagnostic Centre.

When getting the device, expect the following:

Two disposable adhesive electrodes will be positioned on your chest and linked to the recording device by two small cables.

  • The electrodes and monitor should be removed when bathing, showering, and swimming.
  • Electrodes are to be changed every day.
  • The monitor and wires must not come into contact with any liquids or sharp objects such as scissors.

Using the Monitor

The electrodes and recording device are worn for two weeks. Each time a symptom occurs, activate the monitor by pressing the recording button. Keep a diary of each recording listing the date, time, symptoms, and activity whenever symptoms are felt. Some monitors have the capability to detect changes and to initiate recording automatically.

The monitor can store several recordings, and each recording can contain one or more minutes of electrocardiogram (ECG) data.

The content of the recorder is transmitted via telephone line to the monitoring centre at the Heart Institute. The technician will show you how to do this. We suggest that you transmit your recordings after six events. (Note: the recordings cannot be transmitted using cell phones or voice over internet protocol (VOIP).

The transmissions you send are reviewed by the technical staff of the monitoring centre as they are received. Any urgent findings are brought to the attention of a cardiologist. Non-urgent data are compiled and forwarded to a cardiologist for interpretation at the end of the two-week monitoring period.

A report will be mailed to your doctor within 10 business days after the monitor has been returned.

Patient Instructions 

Bring all of your medications in their original containers including any vitamins or supplements that you take. Wear comfortable clothing and please arrive 15 minutes before your scheduled appointment time.

It is important to bring the monitor back at the scheduled time; another patient is waiting.

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