What is a 24 hour Holter monitor?

A Holter monitor is a small portable wearable device that is used to record the heart’s electrical activity (ECG or electrocardiogram) during daily life, including while you are asleep. It provides a continuous recording of the ECG through electrodes that are attached to the skin on your chest. The device is worn underneath your clothing and is left on continuously for 24 hours. The information it obtains is stored on the device and then downloaded onto a computer for analysis and printing.

Why is it done?

There are a number of reasons why your doctor may order a Holter monitor test for you.
Diagnosis of a disturbance of your heart rhythm. This may include looking for heart rhythms that are too slow, too fast or irregular. It is a useful test when people have symptoms of palpitations, dizzy turns, light-headedness, faints or blackouts.
Screening for possible rhythm disturbances in people without symptoms. There are a number of circumstances where people may be suspected of having a rhythm disturbance even in the absence of symptoms. One of these is after a stroke, but there are many others. The Holter monitor is one way to detect otherwise asymptomatic rhythm disturbances.
Monitoring the effects of treatment. People with heart rhythm disturbances may undergo heart monitoring to determine if their treatment is effective.

How is it done?

There are no special preparations. Loose fitting clothes may be more convenient as the device and its wires are placed under your shirt or top. Normal underwear apart from full girdles can be worn. It is important that we know what medications you are taking at the time of the test. An easy way is to bring all your medications with you when you come to have the monitor fitted.

The device is attached with adhesive electrodes after skin preparation around the chest and upper arms. It takes about 10-15 minutes to attach and just a minute or 2 to detach the following day.

You cannot bathe or shower during the test as the device is not waterproof. You should take part in all other life activities, but perhaps avoid very vigorous exercise such as gym or running to avoid dislodging the leads.

The recorder has a button that you can press to record any symptoms you experience such as palpitations, dizziness or chest discomforts. You will also be asked to complete a diary of what you felt, the time of day and what you were doing at the time you experienced the symptoms.

Normally the monitor is removed in our office the following day. However, it can be removed, switched off and brought to the office by someone else for you if needed. Our office will provide more instructions about this at the time of fitting.

What happens after the monitor is removed?

Our technical staff analyse the recording and prepare a preliminary report that is then reviewed and finalised by a cardiologist. This usually takes 1-3 days. Our office will advise you how the results will be communicated to you and your doctors.