If your heart seems to skip a beat, race, or work a bit too slow, you could have a condition known as arrhythmia. Your doctor might suggest you wear a device called a Holter monitor. A Holter monitor is a battery-operated portable device that measures and records your heart’s activity (ECG) continuously for 24 to 48 hours or longer depending on the type of monitoring used. The device is the size of a small camera. It has wires with silver dollar-sized electrodes that attach to your skin. The Holter monitor and other devices that record your ECG as you go about your daily activities are called ambulatory electrocardiograms.

A doctor may ask for Holter monitoring if a person has symptoms such as:

Some reasons for your healthcare provider to request a Holter monitor recording or event monitor recording include:

The Holter monitor is an easy way to assess the heart’s function. Risks associated with the Holter monitor are rare.

It can be hard to keep the electrodes stuck to your skin, and extra tape may be needed. It may be uncomfortable when the sticky electrodes and tape are taken off. If the electrodes are on for a long time, they may cause tissue breakdown or skin irritation at the application site.