Munson Health
Ambulatory Cardiac Monitoring

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by Polsdorfer R

(Holter Monitoring; Ambulatory Electrocardiography [EKG])


What to Expect

Prior to Test

You will first be evaluated by a doctor. An electrocardiogram (ECG) checks the electrical activity of your heart. It will likely be done in the office.

Description of Test

The test steps will depend on the type of device used:
  • Holter monitoring —A small device will be strapped to you. Wires from the device will be attached to electrodes on your chest. Electrodes are small adhesive pads. You may be taught to replace them or asked not to remove them during the monitoring period. You will be instructed to keep a diary of your activities for the next 24-48 hours. You will then return the device and your diary for analysis. Some devices have an event button. You will push the button each time you have concerning symptoms.
  • Looping monitor —The electrode may be a wrist band, finger attachment, or chest plate. This device records several minutes at a time, then starts over. You will push a button during or after an event to save the recording. For longer periods of monitoring, there is an implantable version. This electrode is surgically placed under your skin.
  • Event recorder —This device is only used when you have symptoms. The device can be a wrist band with an activation button or a pager-sized device that you press onto your chest. Some of these are connected to a 24-hour-a-day central base that can immediately detect and respond to the event when you activate the signal.
  • CardioNet (mobile cardiac outpatient telemetry) —A special service monitors your heartbeat continuously. It will respond immediately if it detects a serious event.
Certain environmental interferences should be avoided, including: magnets, metal detectors, high-voltage wires, radio frequency signalers, microwave ovens, electric blankets, electric toothbrushes, and electric razors.

After Test

After the procedure, you will return the equipment.

How Long Will It Take?

A typical interval is 24 hours. If your problem is less frequent than that, you may need to be monitored for a longer period of time. Longer monitoring often requires different devices.

Will It Hurt?

This test will not hurt. Sometimes removing the electrodes can be uncomfortable.


The information recorded by the monitor will be evaluated. Your doctor will let you know if you need any more tests or treatment based on the study.


American Heart Association

Heart Rhythm Society



Canadian Cardiovascular Society

Heart and Stroke Foundation of Canada



Abbott AV. Diagnostic Approach to Palpitations. Am Fam Physician. 2005;71(4):743-750.

Ambulatory monitors. Cleveland Clinic Heart Center website. Available at: Updated September 2013. Accessed August 19, 2014.

Kadish A, Buxton A, Kennedy H, et al. ACC/AHA clinical competence statement on electrocardiography and ambulatory electrocardiography. J Am Coll Cardiol. 2001;38(7):2091-2100.


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