What is this test?

Holter monitoring (also called continuous ambulatory electrocardiographic monitoring) is a continuous monitoring of heart rate and rhythm during your usual daily activities, usually for a 24-hour period.

Why this test may be performed

A Holter monitor is used to identify heart rhythm disturbances, which may come and go at various times throughout the day or night. It is often used to correlate any abnormal heart rhythm with a person's symptoms, such as dizziness, palpitations, shortness of breath or chest pain. The Holter monitor also can evaluate if an artificial pacemaker is functioning properly.

What this test involves

A Holter monitor is applied in a doctor's office, cardiology suite or at the hospital bedside. Electrodes are placed on the front of the chest and the electrode wires are then attached to a small, portable, battery-operated recorder. The recorder is held in place by a shoulder strap or belt that can be worn around the waist. The recorder continuously records and stores the heart rhythm for usually 24 hours. The person is encouraged to continue daily activities. During this time, the person wearing the device keeps a log. Activities such as eating, walking and driving and symptoms such as palpitations, dizziness and shortness of breath should be recorded in the log, noting when they occur. Once the monitor has been removed, a physician analyzes the heart rhythm and activity log.

What are the risks/precautions for this test?

A Holter monitor is a non-invasive test. It is painless and not associated with any risks to the patient. Shower or bathe before the electrodes are applied to the chest, since you won't be able to do these activities while the test is in progress.

What the results may tell you

A Holter monitor may detect a disturbance in heart rhythm that is not evident on a single, resting electrocardiogram tracing. It allows the doctor to correlate specific patient symptoms with the electrical activity of the heart. A Holter monitor can detect rhythm disturbances that are transient or intermittent in nature. Malfunctions in artificial pacemakers can also be detected.