[1] The ILR monitors the electrical activity of the heart, continuously storing information in its circular memory (hence the name "loop" recorder) as electrocardiograms (ECGs).

[5] The ILR is a useful diagnostic tool to investigate patients who experience symptoms such as syncope (fainting), seizures, recurrent palpitations, lightheadedness, or dizziness not often enough to be captured by a 24-hour or 30-day external monitor.

The remaining 30 minutes can be divided into a selectable number of slots for storage of manually triggered retrograde recordings as an answer to symptoms (fainting, palpitations etc.)

In patients with unexplained palpitations, especially those with infrequent symptoms, ILRs have shown a significantly higher diagnostic yield compared to conventional methods.

However, it did not show a significant reduction in the risk of stroke or systemic arterial embolism, indicating that not all screen-detected atrial fibrillation might warrant anticoagulation treatment.