Definition & Overview

An implantable loop recorder insertion refers to the procedure wherein an electrocardiographic monitoring device is subcutaneously implanted into the chest to diagnose heart rhythm issues in the presence of symptoms, such as palpitations or fainting. The device works by keeping track of the patient’s heart rhythm over an extended period of up to two years. The procedure is generally safe and poses only minor risks usually associated with the required incision.

Who Should Undergo and Expected Results

The procedure can be recommended for patients suspected of having a heart rhythm problem and experiencing symptoms, such as:

  • Lightheadedness
  • Dizziness
  • Palpitations
  • Loss of consciousness or fainting
  • Seizures

An implantable loop recorder is specifically useful for patients who do not experience the said symptoms often enough for them to be recorded using 24-hour or 30-day external devices. The device, which can provide 2 years of constant monitoring, can capture even isolated occurrences.

Following the procedure, the device begins to record the heart’s electrical activity. Its goal is to identify any irregularities to confirm whether the symptoms are in fact related to or caused by heart rhythm issues such as atrial fibrillation, myocardial infarction, and genetic disorders affecting the heart.

Regular follow-ups with a cardiologist are scheduled after the procedure to check the recorded information. However, patients can also simply call their cardiologist if they experienced any significant symptoms and used the activator to record it. This way, the cardiologist will arrange for the information to be downloaded at the soonest possible time.

Once enough information has been collected to support a diagnosis, the ILR device can be removed.

How is the Procedure Performed?

The insertion of loop recorder is an outpatient procedure performed by an electrophysiologist, a physician specialising in the heart’s electrical system. After identifying the best position for the device using ECG electrodes, the device is inserted just beneath the skin, usually in the left parasternal region. It will then be programmed to the required settings using radiofrequency before the small incision is closed with dissolvable stitches. The whole procedure, which is performed under local anaesthesia, takes just 15 to 20 minutes. The patient is then given antibiotics to prevent the risk of infection.

Following the procedure, the patient is taught how and when to use the device. To capture and record a specific episode, a handheld activator is simply placed over the chest area where the device was implanted each time symptoms outlined above are experienced.

An implantable loop recorder can store 3 activations at any given time, which means that on the third activation, previous recordings will be overwritten.

Possible Risks and Complications

Although it is a simple procedure, an implantable loop recorder insertion still carries a few risks, including those commonly associated with medical procedures that require an incision or leaves a residual wound such as:

  • Scarring
  • Bleeding
  • Infection


  • Sosin MD., Cadigan PJ., Connolly DL. “Should you remove an implantable loop recorder after the diagnosis is made?” Heart. 2003 Sep; 89(9): 1013.

  • Lammey ML., Jackson R., Ely JJ., Lee DR., Sleeper MM. “Use of an implantable loop recorder in the investigation of arrhythmias in adult captive chimpanzees.” Comp Med. 2011 Feb; 61(1): 71-75.

  • Roebuck A., Mercer C., Denman J., Houghton AR. “Experiences from a non-medical, non-catheter laboratory implantable loop recorder ILR service.” Br J Cardiol 2015 February; 22:36.

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