Continuous recording of the heartbeat for a day or more
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 that only runs for a few seconds. Sending patients home with recorders in position is common practice. It gives a much better idea of what is happening with your heart during your day-to-day activity, than when recording is during a visit to the doctor in the clinic. The Holter monitor gives a better chance to capture any abnormal beats or rhythms that may be only intermittent and short-lasting. 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.
To assess heart rate and rhythm in the presence of fatigue, breathlessness, dizziness and blackouts which may or may be not related to cardiac problem
To obtain ECG correlate to palpitations which allows reassurance if the heart rhythm during symptoms is normal or diagnosis and specific treatment if symptoms correspond to an arrhythmia
To assess level of cardiac risk in certain conditions and situations, e.g. following heart attack with significant damage to the heart muscle (heart failure), hypertrophic cardiomyopathy (thickened heart muscle)
To evaluate chest pain not reproduced with exercise testing
To assess the function of an implanted pacemaker
To determine presence or absence of asymptomatic (silent) arrhythmias, e.g. atrial fibrillation after cardioversion (electric shock to normalize heart rhythm) or catheter ablation for complex arrhythmias
Risks and complications
The Holter monitor is a noninvasive test and there are no known risks with this investigation. Although non-allergic stickers will be used, some patients, on rare occasions, may experience some itching underneath the tab caused by transient skin irritation. Should you have any worries about the procedure Dr Kirk will be only too pleased to discuss them with you.
Before the procedure
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 and to sit down. 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 hours to a week). You will be given a diary card. You need to record any symptoms you have and the exact time you had them (including whether it is am or pm) and what you were doing before the symptoms. This is helpful when playing through the recording to compare your symptoms with what your heart is actually doing. This information is of particular importance. 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. When you are confident that you will be able to do this, you will be able to go home. The whole process takes approximately 15 minutes.
During the procedure
Once you have been hooked up to the monitor and given instructions, you can return to your usual activities, such as work, household chores, sport and exercise. 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
Before the procedure
You will be taken into the room where the test is to be performed. The test will be explained and you will be asked to remove any necessary articles of clothing above the waist. Since access to your ankles is needed, it is helpful if ladies could avoid wearing tights. Some electrode pads will be stuck onto your chest and limbs to which wires going to the ECG recorder will be attached. It is helpful for this test if you can remove any jewellery from your neck before you arrive.
You will be instructed to keep a diary of your activities. You should write down the date and exact time of your activities and corresponding symptoms, such as chest pain, breathlessness, dizziness or lightheadedness.
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.
After the procedure
You must return the following day to have the recorder removed, a visit lasting approximately 5 minutes. 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.