Continuous recording of the heartbeat for 24 hours
An ECG is one of the basic and simplest methods used to assess the heart. Electrodes (adhesive plastic patches) are placed on the chest and connected to an ECG machine which records a snapshot of the electrical activity of the heart. When conclusive diagnosis cannot be obtained with a resting ECG and symptoms such as such as palpitations, dizziness, lightheadedness or blackouts continue, a prolonged ECG recording using the Holter monitor may be necessary.
24-hour ECG monitor continuously records electrical activity of the heart for the whole day or more, making it possible to assess overall heart rate and presence of transient arrhythmias (heart rhythm problems) which may be missed on standard ECG. A heart monitor gives a much better idea of what is happening with the heart rhythm during normal day-to-day activities than a short ECG recording in doctor's surgery. The Holter monitor gives a better chance to capture any abnormal beats or rhythms that may be only intermittent. An event monitor function, that you activate when your symptoms occur, allows correlation between ECG and symptoms.
The monitor is about the size of a mobile phone and attached to a belt or hung around the neck. You will be asked to keep a diary of any symptoms so that their correlation to recorded ECG is possible. You should go about your normal daily routine as usual with the monitor in place to get a representative recording of your heart activity.
The Holter monitor is a noninvasive test with no known risks. Non-allergic stickers will be used but rarely some patients may experience transient skin irritation.
The procedure will be explained and you will be offered the opportunity to ask any questions about the test. It is helpful for this test if you can remove any jewellery from your neck. The areas where the electrodes are to be placed may need to be shaved. You will be asked to remove all your clothing above the waist, including any underwear. Your privacy will be protected by covering you with a sheet or gown and exposing only the necessary skin. Several sticky pads will be placed onto your chest and attached with wires to the recorder. The monitor box may be worn over the shoulder like a shoulder bag, or it may clip to a belt or pocket. You will receive instructions regarding how long you will need to wear the recorder (usually 24 to 48 hours). You will be given a diary card to record any symptoms you may have, the time of the symptoms and what you were doing. This is helpful when correlating your symptoms to potential arrhythmias on the ECG monitor. You will also be asked to record you activities throughout a day (i.e. on a walk from 1 to 2.30 pm etc.), when you go to bed, when you get up and what medication you are taking and when. The whole process of attaching the monitor takes approximately 15 minutes.
Once you have been hooked up to the monitor and given instructions, you can return to your usual activities. You should go about your normal routine so that a representative recording can be obtained. If the Holter is indicated for transient problems, it is useful to try and replicate situations which normally trigger the symptoms in order to obtain ECG correlate. You will be instructed to keep a diary of your activities and symptoms as explained above. Close proximity to sources of strong electromagnetic field, such as magnets or metal detectors may affect the quality of recording. Excessive perspiration may cause detachment of the leads.
You must return the monitor the following day. The recording will be played through and analyzed. The report will be discussed with you during follow-up appointment and depending on the result, an appropriate action will be taken. You will be able to resume your normal activities; there is no special care following Holter monitoring.