A Holter monitor is used to monitor and record the heart's electrical activity over a set period, usually 24 hours. An Event Recorder is the same type of monitor but allows recording of abnormal heart rhythms for one month.

What is the procedure?

The Holter monitor is a small, ambulatory, portable ECG machine that can provide the following information:

• The heart's rhythm over a 24-hour period, during normal activities, or recording gets triggered by the patient when a specific event occurs.  An event recorder can be used for a much longer period of time.
• Correlate any symptoms (chest pain, palpitations, etc.) the patient experiences with the heart's electrical activity at that time.
• Record any abnormal heart rhythms (arrhythmias) that occur, providing diagnostic information about the type of arrhythmia, how long it lasts, and what might trigger it.
• Determine how well anti-arrhythmia medicines are working.

The Holter monitor is worn over a 24-hour period while the patient does all of his/her normal activities. Small, sticky patches called electrodes are attached to the chest. Wires travel from the electrodes to a small portable box that is worn on the belt or shoulder strap. The box records and stores continuous heart rhythm data transmitted by the electrodes. The patient must keep a diary of activities, and of any symptoms, that occur while the monitor is in place. This will allow the doctor to correlate activities and symptoms with the heart’s electrical rhythm at a specific point in time. The patient will also be advised of how to care for the monitor while wearing it. When the 24-hour period is complete, the patient returns the Holter monitor to the hospital, and a technician does a computerized analysis of the Holter monitor data to prepare a thorough report for the physician.

Useful tips for better recording quality.

• Wear a two piece outfit, preferably a shirt with buttons on the front.

• Try to sleep on your back with the recorder positioned at your side so that the electrodes are not pulled off.

• Do not get the electrodes, wires or monitor wet. Sponge bathing is permitted.

• If you have a hairy chest, the areas where the electrodes are placed will need to be shaved.

• Avoid electric blankets, heating pads, magnets, metal detectors, and high voltage areas such as power lines. Signals from such devices may affect recording.

• It is important that you keep the electrodes and wires attached for the entire recording. If an electrode comes off, stick it back on your skin.

Where is the test performed?

The Holter monitor is placed on the patient at the hospital or clinic. The actual testing period occurs at the patient's home (or wherever the usual daily routine takes place). At the end of the test or designated time period, you may remove the patches and return the recorder to the hospital or clinic from which you received it.

How long does this test take?

The Holter monitor placement and instructions take about 10 to 20 minutes to complete.

6/16/2008