A Holter monitor is a small, battery-powered medical device that measures your heart’s activity, such as rate and rhythm. You may be asked to use one if more information is needed about how your heart functions than a routine electrocardiogram (EKG) can give.
Twenty-four hour Holter monitoring is a continuous test to record your heart’s rate and rhythm for 24 hours. You wear the Holter monitor for 12 to 48 hours as you go about your normal daily routine. This device has electrodes and electrical leads exactly like a regular EKG, but it has fewer leads. It can pick up not only your heart’s rate and rhythm but also when you feel chest pains or exhibit symptoms of an irregular heartbeat, or arrhythmia.