Cardiac Loop Event Recorder (LER)

Cardiac Loop Event Recorder (LER)2018-12-17T22:41:40+00:00

What is a cardiac loop event recorder?

A cardiac loop event recorder is a battery-powered portable device that you control to tape-record your heart’s electrical activity (ECG) when you have symptoms. There are two types of event recorders: a loop memory monitor and a symptom event monitor. Cardiac event recorders and other devices that record your ECG as you go about your daily activities are also called ambulatory electrocardiographic monitors.

Quick facts:

  • A cardiac loop event recorder makes a record of your electrocardiogram (ECG or EKG) when you have fast or slow heartbeats, or feel dizzy or like you want to faint. It can also be used to see how you respond to medicines.
  • Some cardiac event recorders store your ECG in memory in the monitor. Your ECG can be sent by telephone to a receiving center or to your doctor.
  • There are no risks when using a cardiac event recorder.

I kept feeling this pounding in my chest. My doctor suggested I wear an event recorder, and soon I was put on medicine to control my fast heartbeat. – Kay, age 61

Why do people need to use a cardiac event recorder?

Tests such as electrocardiograms let your doctor look at your heart’s activity at rest and at one point in time. But abnormal heart rhythms and cardiac symptoms may come and go. The main purpose of an event monitor is to record your heart rate and rhythm during a symptom (“event”). They work only when a person turns on the device. Your doctor may recommend an event monitor when symptoms are infrequent – less than daily.
You may be asked to wear a cardiac event recorder if you have fast, slow or irregular heartbeats called arrhythmias.

Wearing the monitor may tell your doctor:

  • If your medicines are working.
  • If a pacemaker or an implantable cardioverter defibrillator (ICD) is working properly.
  • Why you have symptoms such as chest pain, dizziness, faintness or the feeling that your heart is racing or skipping a beat.
  • If your heart is getting enough oxygen to meet its needs.



  • The electrodes (small sticky pads) need to be attached securely to the skin on your chest to get a clear recording.
  • Wipe skin clean with an alcohol swab. Dry with the gauze pads provided before attaching the electrodes to your chest.
  • Attach the electrodes to the lead wires before attaching the electrodes to your chest.
  • Attach the electrodes on your chest in the position shown in the diagram.
  • White lead wire to right electrode, black lead wire to left electrode.
  • Press electrode firmly to skin.
  • Discard any electrodes with dry gel.
  • Change the electrodes each day, or more often if they are loose/not sticking well.
  • Insert the plug from the lead wires into the top of the recorder/monitor after you have attached the electrodes to your chest.
  • Secure the monitor.


  • When you have your heart symptom (such as dizziness, chest pain, palpitations, light-headedness, shortness of breath) press the RECORD button on the monitor.
  • Relax and remain still while the device is recording.
  • You will hear a series of 5 tones or “beeps” which lets you know it has stopped recording.
  • After recording, you will see an “F” in the display window. This means the monitor is full and cannot record any more. You must transmit, that is, send in your recording. The device will continue to beep every few minutes until you transmit your recording.
  • Sometimes, the record button may be pressed by mistake. If so, the monitor will beep a series of 5 tones and a “F” will appear in the display window. You do not need to transmit this recording, but you do need to erase it. Unplug the lead wire at the top of your monitor and press the send button on the side of the monitor. When the whistling sound stops, plug the lead wire back in.


  • You must use a regular telephone (a landline) to send in your recording. Do not use a cell phone or a cordless telephone.
  • Remove the lead wire plug from the top of the monitor.

Remember that:

  • your home telephone number is always your identification number.
  • The # symbol on your telephone is called the “pound” key.

Call 905-597-7111 when you are ready to send in your recording and follow the instructions on the telephone which include:

  • State your full name, the date and the time.
  • Your symptoms when you recorded.
  • Where you were and what you were doing when you recorded.
  • Place the monitor face-up on a table or flat surface next to your telephone.
  • Place the mouthpiece (the part you speak into) of the telephone over the RECORD button of your monitor. Press the SEND button (located on the side) to start the transmission. You will hear a whistling sound.
  • After the transmission is complete, the whistling sound will stop. You may plug the lead-wire back into the monitor.


Check the batteries each time you turn on the monitor. If the battery symbol appears on the monitor, the battery is low and must be replaced with 2 AAA batteries (2 triple A batteries).

Bathing or Showering

You must disconnect the lead wire plug and remove the monitor and electrodes to bath or shower.

If you have problems with your recorder

If you have questions or concerns about the operation of your recorder, call 905-597-7111 and leave a message on the answering machine. A technologist will receive your message and will call you back within 24 hours during weekdays (Monday to Friday, 9am – 4 pm). If you are concerned about your heart symptoms, contact your doctor.