St. Luke's Hospital
Located in Chesterfield, MO
Main Number: 314-434-1500
Emergency Dept: 314-205-6990 Patient Billing: 888-924-9200
Find a Physician Payment Options Locations & Directions
Follow us on: facebook twitter Mobile Email Page Email Page Print Page Print Page Increase Font Size Decrease Font Size Font Size
Meet the Doctor
Spirit of Women
Community Health Needs Assessment
Home > Health Information

Multimedia Encyclopedia


    Holter monitor (24h)

    Ambulatory electrocardiography; Electrocardiography - ambulatory

    A Holter monitor is a machine that continuously records the heart's rhythms. The monitor is usually worn for 24 - 48 hours during normal activity.

    How the Test is Performed

    Electrodes (small conducting patches) are stuck onto your chest and attached to a small recording monitor. You carry the Holter monitor in a pocket or small pouch worn around your neck or waist. The monitor is battery operated.

    While you wear the monitor, it records your heart's electrical activity.

    • Keep a diary of what activities you do while wearing the monitor, and how you feel.
    • After 24 - 48 hours, you willreturn the monitor to your doctor's office.
    • The doctor will look at the records and see if there have been any abnormal heart rhythms.

    It is very important that you accurately record your symptoms and activities so the doctor can match them with your Holter monitor findings.

    Electrodes must be firmly attached to the chest so the machine gets an accurate recording of the heart's activity.

    While wearing the device, avoid:

    • Electric blankets
    • High-voltage areas
    • Magnets
    • Metal detectors

    Continue your normal activities while wearing the monitor. You may be asked to exercise while being monitored if your symptoms have occurred in the past while you were exercising.

    How to Prepare for the Test

    There is no special preparation for the test. Your doctor will start the monitor. You'll be told how to replace the electrodes should they fall off or become loose.

    Tell your doctor if you are allergic to any tape or other adhesives. Make sure you shower or bathe before you start the test. You will not be able to do so while you are wearing a Holter monitor.

    How the Test Will Feel

    This is a painless test. However, some people may need to have their chest shaved so the electrodes can stick.

    You must keep the monitor close to your body. This may make it hard for you to sleep.

    Why the Test is Performed

    Holter monitoring is used to determine how the heart responds to normal activity. The monitor may also be used:

    • After a heart attack
    • To diagnose heart rhythm problems
    • When starting a new heart medicine

    It may be used to diagnose:

    • Atrial fibrillation or flutter
    • Multifocal atrial tachycardia
    • Palpitations
    • Paroxysmal supraventricular tachycardia
    • Reasons for fainting
    • Slow heart rate (bradycardia)
    • Ventricular tachycardia

    Normal Results

    Normal variations in heart rate occur with activities. A normal result is no significant changes in heart rhythms or pattern.

    What Abnormal Results Mean

    Abnormal results may include various arrhythmias. Changes may mean that the heart is not getting enough oxygen.

    The monitor may also detect conduction block, a condition in which the atrial electrical activity is either delayed or does not continue into the ventricles of the heart.


    There are no risks associated with the test. However, you should be sure not to let the monitor get wet.


    Miller JM, Zipes DP. Diagnosis of cardiac arrhythmias. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 36.

    Olgin JE. Approach to the patient with suspected arrhythmia. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 62.


    • Ventricluar fibrillation...


    • Holter heart monitor


    • Ventricluar fibrillation...


    • Holter heart monitor


    Talking to your MD

      Self Care

        Tests for Holter monitor (24h)

        Review Date: 6/22/2012

        Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Michael A. Chen, MD, PhD, Assistant Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.

        The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

        A.D.A.M. content is best viewed in IE9 or above, Fire Fox and chrome browser.

        Back  |  Top
        About Us
        Contact Us
        Locations & Directions
        Quality Reports
        Annual Reports
        Honors & Awards
        Community Health Needs

        Brain & Spine
        Sleep Medicine
        Urgent Care
        Women's Services
        All Services
        Patients & Visitors
        Locations & Directions
        Find a Physician
        Tour St. Luke's
        Patient & Visitor Information
        Contact Us
        Payment Options
        Financial Assistance
        Send a Card
        Mammogram Appointments
        Health Tools
        My Personal Health
        Spirit of Women
        Health Information & Tools
        Clinical Trials
        Employer Programs -
        Passport to Wellness

        Classes & Events
        Classes & Events
        Spirit of Women
        Donate & Volunteer
        Giving Opportunities
        Physicians & Employees
        For Physicians
        Remote Access
        Medical Residency Information
        Pharmacy Residency Information
        Physician CPOE Training
        St. Luke's Hospital - 232 South Woods Mill Road - Chesterfield, MO 63017 Main Number: 314-434-1500 Emergency Dept: 314-205-6990 Patient Billing: 888-924-9200
        Copyright © St. Luke's Hospital Website Terms and Conditions  |  Privacy Policy  |  Notice of Privacy Practices PDF  |  Patient Rights PDF Sitemap St. Luke's Mobile