Holter Monitors

What is a Holter monitor?

A Holter monitor is a device that records the electrical activity of your heart on a tape cassette for 24 to 48 hours. You wear the monitor and place signals on the tape to mark symptoms or events. They are also called ambulatory electrocardiographic monitors (AEMs).

When is it used?

Holter monitors are mostly used to observe and record abnormal heart rhythms. They are sometimes used to look for times when the heart muscle is not getting enough blood flow through the coronary arteries.

Heartbeats that are either too fast or too slow may cause lightheadedness or fainting. However, these symptoms may not happen while you are in your healthcare provider's office or in an emergency room. The Holter monitor checks the heart rhythm while you are performing usual daily activities. It can also be used to:

• evaluate chest pain
• evaluate a new pacemaker
• check the effectiveness of medicines.

Symptoms such as dizziness, palpitations, shortness of breath, fainting spells, and chest pain may have many different causes. A Holter monitor is used to find out if your heart is causing your symptoms.

The importance of irregular heartbeats depends on:

• if they occur at the same time that you have symptoms
• how often they occur
• how long they last
• the type of pattern they produce.

The Holter monitor can alert your healthcare provider to possible problems and help your provider decide on a treatment.

What happens during the procedure?

In the healthcare provider's office, the hospital, or clinic you will be asked to take off your clothes down to the waist. Men will have portions of their chest hair shaved. Sticky electrodes are put on your chest with adhesive. The electrodes are attached to a small tape recorder. The recorder is carried on a belt or shoulder strap.

You will be given a diary to record your activities or symptoms for the next 24 or 48 hours. It is very important that you write down your activities and symptoms.

Wear loose fitting clothes while wearing the monitor. Do not shower while wearing the monitor.

What happens after the procedure?

When you return to the office or clinic, the electrodes will be removed. The tape and diary will be reviewed. Your provider will discuss the results with you at your next visit, or sooner if needed. You may need to wear a Holter monitor more than once, such as if you switch to a new medicine.