A loop recorder is an implantable EKG monitoring device. It cannot detect heart attacks or strokes. However, it can help doctors diagnose certain heart conditions to determine suitable treatments.

A loop recorder records the heart’s electrical activity over an extended period and can record for up to 3 years.

This article looks at what a loop recorder is, why doctors use it, and what to expect during and after the procedure. We also look at what a loop recorder’s results might mean.

A loop recorder on a person's chest to detect heart problemsShare on Pinterest
Medical Illustration by Bailey Mariner

A loop recorder, also known as an insertable cardiac monitor, is a small device that a doctor implants under the skin to record electrical activity in the heart. Doctors use this information to diagnose heart rhythm disorders.

A loop recorder constantly monitors heart rhythm and can record EKG “snapshots” in case of bradycardia, a slow heart rate, or tachycardia, a fast heart rate.

A loop recorder is a miniature device, and the latest models are small enough for doctors to inject them.

Doctors use loop recorders to see how a person’s symptoms correlate with EKG findings, which can help them make an accurate diagnosis and choose the most effective treatment.

Doctors typically use a loop recorder to evaluate recurring palpitations in people, and episodes of syncope, or fainting, of unknown causes. Doctors may also use a loop recorder to assess bradycardia before implanting a permanent pacemaker.

However, manufacturers do not design loop recorders to detect specific heart problems, such as:

However, they can help a doctor make a diagnosis according to the heart’s rhythm, which may help them detect such conditions or refine their treatment of existing conditions.

A loop recorder may also help doctors:

  • evaluate a patient’s outlook following an acute coronary event, such as a heart attack, due to a sudden reduction of blood to the heart
  • identify episodes of atrial fibrillation, an irregular heartbeat that can cause poor blood flow, after a stroke
  • screen a person with cardiac syndromes for ventricular premature beats — extra heartbeats due to atypical electrical activity in the lower chambers of the heart — and tachycardia
  • assess a person’s average heart rate and adequacy of rate control during atrial fibrillation

An electrophysiologist typically inserts this implant during an outpatient procedure. It is minimally invasive and does not usually require sedation.

The procedure is as follows:

  1. A doctor will administer local anesthesia to numb a person’s skin at the insertion site.
  2. They will make a small incision near the second or third rib on the left side.
  3. They will create a small pocket under the skin and insert the loop recorder.
  4. The doctor will then close the incision with stitches.
  5. Finally, they will pass a magnet over the device to activate it.

The device will create a slight lump, which the doctor will cover with a bandage. The procedure takes about 10–15 minutes.

A person could leave the hospital on the day of the procedure and may require some pain medication.

However, they may experience complications, including:

  • infection in the pocket that holds the loop recorder
  • pain at the site of the implant
  • skin reaction to the device
  • rarely, the loop recorder may incorrectly sense an electrical impulse called an R wave, and a doctor may have to move the device

A loop recorder sends recordings to a person’s medical professional, sometimes through a small transmitter within the individual’s home. Depending on the device, the results may send automatically to a doctor. Alternatively, the person will need to attend the hospital so that doctors can download the results from the recorder.

Once the medical team has the results, they will create a report. A loop recorder report includes information about:

  • the EKG tracings
  • the technician’s interpretation of the EKG
  • symptoms that the person reported during the monitoring phase

According to the report, a doctor can diagnose and make treatment recommendations.

If the report shows EKG abnormalities that correlate with a person’s symptoms, a doctor can diagnose and make treatment recommendations. These treatments may include the following:

If a person had symptoms but did not have corresponding EKG abnormalities, the doctor will investigate other possible causes, as they may not relate to the heart. A doctor may also refer a person to a different specialist.

If someone has no EKG abnormalities or symptoms, the doctor can remove the device and stop monitoring the heart.

A loop recorder is a small implantable device that records electrical impulses in the heart. Doctors can use the EKG results and a person’s other symptoms to diagnose certain heart conditions and advise treatment approaches.

Implanting a loop recorder is an outpatient procedure, which is minimally invasive and typically requires a local anesthetic.

According to the results of the loop recorder and the person’s symptoms, doctors may prescribe medications, recommend implanting a permanent pacemaker or cardiac defibrillator, suggest further testing, or perform a therapeutic procedure.