An implantable loop recorder (ILR) is a small, subcutaneous device designed to continuously monitor the heart’s electrical activity. This miniature device, similar in size to a USB stick or AAA battery, is placed under the skin in the chest. Its purpose is to capture heart rhythm information over an extended period, providing detailed data on a person’s heart function during daily life.
Why a Loop Recorder is Recommended
Healthcare professionals often recommend an implantable loop recorder when a person experiences symptoms that suggest an irregular heart rhythm, but these symptoms occur infrequently or unpredictably. Conditions such as unexplained fainting episodes, recurrent palpitations, dizziness, or certain types of stroke, may prompt consideration for an ILR. Standard diagnostic tests, like a 12-lead electrocardiogram (ECG) or a short-term Holter monitor, might miss these brief or rare events. The ILR offers long-term monitoring, up to three years or more, significantly increasing the chances of capturing these elusive heart rhythm disturbances. This prolonged observation helps identify the underlying cause of symptoms that are not consistently present.
How Loop Recorders Capture Information
The implantable loop recorder functions by continuously tracking the heart’s electrical signals, similar to how an electrocardiogram operates. It constantly records this information into its memory, creating a “loop” of electrical activity. The device is programmed to automatically store segments of this recorded data when it detects predefined abnormal heart rhythms, such such as rates that are too fast or too slow. Individuals can also manually activate the recorder if they experience symptoms like lightheadedness or skipped beats. This manual activation ensures that the heart’s activity during a symptomatic event is saved for later review by a healthcare team.
The Implantation Procedure
Implanting a loop recorder is typically a minor outpatient procedure, meaning a hospital stay is usually not required. Before the procedure, the chest area is numbed with a local anesthetic, and a mild sedative might be offered. A small incision, usually less than an inch, is made on the left side of the chest to create a pocket beneath the skin, where the loop recorder is inserted. The incision is then closed with stitches, surgical glue, or adhesive strips. The procedure is quick, taking about 10 to 15 minutes, and most people can go home the same day.
Life with a Loop Recorder and Data Monitoring
After implantation, individuals can typically resume most daily activities with few restrictions, as the internal device has no external wires or patches, allowing for normal showering and exercise. Healthcare providers establish a follow-up schedule to retrieve stored data. Data is often wirelessly transmitted from the ILR to a home monitor, which then sends information to the healthcare team for review. This remote monitoring allows for continuous oversight without frequent clinic visits. The battery life of an implantable loop recorder ranges from two to four years, with some models lasting up to 4.5 years. When the device is no longer needed or approaches the end of its battery life, it can be removed through a similar minor procedure.