Holter Monitor Procedure: What is Going to Happen During My Test?

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Holter Monitors

Each year, physicians must diagnose thousands of heart conditions across the country. Conditions that are not life-threatening can be tested and recorded outside of the hospital with the use of a Holter monitor. A Holter monitor is a portable device that records the electrical impulses that cause the heart to beat at a regular interval. They measure the electrical activity of the heart, just like an electrocardiogram (ECG or EKG) in a hospital. They are designed in order to allow patients to continue with their daily activities and schedule, specifically to measure heart conditions that maybe did not present themselves while being tested at the hospital.

These devices are generally used to diagnose irregular heart rhythms, called arrhythmias. However, they may also be used to test the cause of dizziness, shortness of breath, chest pain or to check the heart’s function following a heart attack or the implantation of a pacemaker.

Before the Test

On the day of your appointment, it is necessary to make certain preparations to be ready for the Holter monitor procedure. Patients should bathe or shower. This is important because during the time you will be wearing a monitor, you will be unable to shower. The monitors are not waterproof, therefore cannot get wet, and they must remain attached for the full length of time.

Men with hairy chests will most likely be required to shave part of their chest and torso. This is to allow the sticky pads, called electrodes, to stick to the skin. Aside from this there is no other special preparation required. It is, however, a good idea to wear a loose, button-up shirt to not interfere with the leads or cause them to become loose.

During the Test

After a technician has fitted you with your monitor, they should explain how it works. There are many different brands, so the appearance will differ from hospital to hospital. However, they should all have an “Event” button. Should you experience any cardiac symptoms, press the button and it will be recorded along with a continuous record of your heart rhythm. During your Holter monitor procedure, you should carry on with normal daily activities and eat and drink normally. Avoid activities that cause excessive perspiration, as well as electrical appliances, magnets, electric blankets and metal detectors as they can cause electrical interference.


Along with your Holter monitor, your doctor will give you a diary for the time you wear your device. This may be from 24 to 72 hours, but normally only lasts one day. In your diary, you should write down the time and type of activity performed, along with any symptoms you experienced during them, such as shortness of breath, skipped heartbeats or chest pains. Also note any contact with electrical devices that may have caused interference with the test. The physician will compare this information with the EKG record from your monitor when the test is over.

After the Test

After the allotted time has passed, you will return to your physician’s office or the hospital and return the Holter monitor and your diary. When the electrodes are pulled off, you may experience some discomfort akin to having a bandage pulled off. A specialist will interpret the data collected, and your physician will make a diagnosis with this information or prescribe other tests.


Mayo Clinic: Holter Monitor: What You Can Expect

Harvard Health Publications: Holter Monitor

University of Pittsburgh Medical Center: Holter Monitor

Cleveland Clinic: Ambulatory Monitors

National Heart Lung and Blood Institute: EKG Holter and Event Monitors

Children’s Hospital of Pittsburgh: Holter Monitoring

Johns Hopkins Medicine Heart and Vascular Institute: Holter Monitor

University of Alabama at Birmingham: Holter Monitoring

University of Maryland Medical Center: Holter Monitor (24h)

Robert Wood Johnson University Hospital: Heart Procedures-Holter Monitor

Oregon Health and Science University Health Information: Holter Monitoring

University of Rochester Medical Center: Heart Procedures-Holter Monitor