A Holter monitor is a small, wearable device that keeps track of your heart rhythm. It is a noninvasive test that uses electrodes taped to your chest to check your heart's rhythm. Your doctor may want you to wear a Holter monitor for one to seven days. During that time, the device records all of your heartbeats.
Your doctor uses information captured on the Holter monitor to figure out if you have a heart rhythm problem. If standard Holter monitoring doesn't capture your irregular heartbeat, your doctor may suggest an implantable loop recorder.