Implantable Loop Recorder

Ambulatory electrocardiogram (ECG) monitoring is an invaluable tool to assess and establish a diagnosis of a patient's symptoms. There are a variety of possible ambulatory ECG monitors to choose from. Holter monitors are used to record 24 to 48 hours of activity. Event monitors can record 2 to 4 hours of activity. Implantable loop recorders can record for up to 3 years. The choice among these technologies is usually based on the suspected monitoring duration that will be required to capture a spontaneous event. Thus, if symptoms occur daily, a Holter monitor may be adequate. If symptoms occur weekly or monthly, an event monitor may be best. If symptoms occur less than monthly or even a few times per year, then an implantable loop recorder is likely the best option. Typical event recorders may not be useful at all if the patient collapses and cannot activate the device. Because of such, a device that can activate on its own and/or has memory to retain information for later download is preferred. This article will cover implantable loop recorders.[1][2][3] The implantable loop recorder (ILR) is a subcutaneous monitoring device used to monitor electrical activity of the heart over an extended period, compared to the fixed picture of electrical activity that is seen with ECGs.[4]