Implanted loop recorders (ILRs) also known as insertable cardiac monitors (ICM) commonly used to record and monitor electrocardiography (ECG) over a 2 to 4 year time period. Holter monitors and external loop recorders are short term recording devices. They can monitor ECGs for up to 30 days. They can be worn with electrodes (holter monitors), around the chest with a belt with no electrodes, as a patch, or a smart watch. Internal loop recorders (ILR) are small devices that are designed for subcutaneous implantation in the chest wall. They can be fixed into the chest wall to reduce the number of artifacts on the EKG that are attributed to instability of the device. This document provides an overview of these products and current evidence regarding their use.