A Holter monitor is a small, battery-powered medical device that measures your heart’s activity, such as rate and rhythm. Your doctor may ask you to use one if they need more information about how your heart functions than a routine electrocardiogram (EKG) can give them.
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.
The Holter monitor may reveal that your medicine isn’t working or your dosage needs to be altered if you’re already taking medication for an abnormal heart rhythm. It’s especially useful in detecting abnormal heart rhythms that are painless and unknown to you.