Implantable Loop Recorder
An implantable loop recorder (ILR) is a small device implanted just under the skin of the chest; it monitors and records the electrical activity of the heart for up to 18 months. The typical reason for implantation is to diagnose and control heart arrhythmia and its associated symptoms, such as skipped heartbeats, lightheadedness, dizziness or fainting (syncope), that occur too infrequently to be captured by Holter monitors.
The ILR automatically records electrical activity if the heart rate rises over, or dips under, normal parameters. The record feature can also be activated by the patient when she or he is having symptoms. Recordings are stored in the device, and then viewed at the doctor's office.
Implantable-Loop-Recorder Placement
A tilt table test and an electrophysiology study are normally administered prior to ILR implantation. On the day of the procedure, the patient is admitted to the hospital. An intravenous (IV) line is inserted to administer sedatives, medications and fluids during the test. The implantation site is anesthetized, and the doctor makes an incision alongside the sternum, creating a pocket into which the ILR is inserted. Once correctly placed, the device is tested to ensure that it is correctly recording the heart's electrical activity, and the incision is closed with dissolvable sutures.
The device is able to record any number of arrhythmia or cardiac events for up to 18 months, and is removed once a diagnosis is made or, in some cases, when its battery wears out. A patient can return home the day of the procedure with few restrictions on activity.
Complications of an Implantable Loop Recorder
ILR placement carries only a small risk of complications. Although patients can experience some bruising and discomfort at the incision site for a few weeks, pain or infection is unusual. In rare cases, the device may have to be repositioned within the chest.