Holter Monitoring (24-hr)
A focused scan for 24-hr rhythm, Palpitations, Silent ischaemia.
Overview
Examines 24-hr rhythm, Palpitations, Silent ischaemia. Performed at an NABL-accredited Meridian Health centre with a same-day report and a free doctor review.
The full panel
3 areas across 1 groupEvery parameter, grouped by body system — no clicking to expand.
What this scan measures
Your heart rhythm continuously for 24 hours while you go about a normal day. A small recorder with chest electrodes captures every beat, and the analysis reports the minimum, maximum and average heart rate, the total number and pattern of ectopic beats, any pauses, and any runs of abnormal rhythm — correlated against the diary you keep of symptoms and activity.
A resting ECG lasts ten seconds and an arrhythmia that comes and goes will usually be absent during it. Holter monitoring is ordered for palpitations, unexplained dizziness or blackouts, to check the adequacy of rate control in atrial fibrillation, and to look for silent pauses in people with conduction disease.
Symptoms that lead to this scan
- Palpitations or an awareness of skipped or racing beats
- Dizziness, light-headedness or blackouts
- Known atrial fibrillation, to assess rate control
- Fatigue with a very slow or irregular pulse
- After a stroke of unknown cause, to look for atrial fibrillation
Understanding your results
Occasional ectopic beats are found in most healthy people and are usually of no consequence — the report will quantify them, and a small burden is generally reassuring rather than alarming. The most valuable part of the study is the correlation between your diary and the trace: symptoms occurring with a completely normal rhythm is itself an important, reassuring result. A 24-hour recording can still miss an infrequent arrhythmia, so a longer or event-triggered monitor is sometimes needed afterwards.
Why the preparation matters
Come with a clean, dry chest and no oil, powder or moisturiser — the electrodes rely on adhesive contact for a full day, and a detached lead means a lost recording. Chest hair is usually trimmed at the electrode sites. You cannot shower or bathe while the monitor is on, so wash beforehand. The most important instruction is to live NORMALLY and keep an honest diary of times and symptoms; deliberately resting to protect the recording defeats the purpose, because the point is to capture the rhythm during the activity that provokes your symptoms.
Cardiac — safety and who should not be scanned
Full Cardiac guideNone of these tests uses ionising radiation — there is no X-ray dose at all in an ECG, an echocardiogram, a Holter or a treadmill test, and they can be repeated as often as clinically useful. The risk lies somewhere else entirely, and it belongs specifically to the stress tests: pushing the heart hard is how the test works, and in a small number of people that provokes chest pain, a significant rhythm disturbance or a fall in blood pressure. That is exactly why a stress test is performed in a room with a doctor present, continuous monitoring and a defibrillator to hand, why it is stopped the moment a stopping rule is met, and why it is not done at all when the heart is known to be unstable. A resting ECG or echocardiogram carries no such risk.
- Unstable chest pain, or a recent heart attack
- Chest pain that is new, worsening or happening at rest, and a heart attack within the last few days, are reasons not to perform a stress test — the test asks the heart to do the very thing that is already failing. Resting tests are safe and are usually what is done instead. Stress testing after an infarct happens later, on a defined protocol, once the picture is stable. The same applies to acute inflammation of the heart muscle or its lining, and to any acutely unwell patient.
- Uncontrolled arrhythmia, or severe aortic stenosis
- A rhythm disturbance that is not controlled, and a severely narrowed aortic valve causing symptoms, both make exercise testing hazardous, because exercise is what tips each of them over. An echocardiogram is done first in anyone with a known or suspected valve problem, precisely so this is known before a treadmill is considered.
- Blood pressure that is very high on the day
- Exercise raises blood pressure further, so it is measured before the test starts and a treadmill test is deferred when the reading is well above target — departments commonly use a threshold in the region of 200 systolic or 110 diastolic. This is a postponement, not a cancellation: the test is rebooked once the pressure is controlled.
- Being unable to walk on a treadmill
- Arthritis, a previous stroke, peripheral arterial disease, severe breathlessness at rest or any mobility limitation makes a treadmill test either unsafe or uninterpretable, because the heart never reaches the workload the test depends on. There is a well-established alternative — a pharmacological stress test, where a drug is given into a vein to make the heart behave as if it were exercising. Say what you can and cannot manage when you book, so the right test is arranged first time.
- Asthma or wheezy lung disease, if a vasodilator drug is planned
- Adenosine and dipyridamole, the drugs used for vasodilator stress testing, can trigger severe bronchospasm in people with asthma or other bronchospastic lung disease, and they are avoided in that situation. Dobutamine, which works differently, is generally used instead. Tell the team about any wheeze, inhaler use or lung disease before the test is booked, not on arrival.
- Caffeine and certain medicines before a pharmacological stress test
- Caffeine directly blocks the drugs used for vasodilator stress, so a scan can be wasted by a single cup of coffee. Avoid coffee, tea, cola, energy drinks, chocolate and decaffeinated coffee for 12 to 24 hours beforehand as instructed, and mention any theophylline-based tablet or inhaler. Which of your regular heart medicines to take or hold on the morning of a stress test — beta blockers especially, since they blunt the heart-rate response and can make the test uninterpretable — is decided by the doctor who requested it, never on your own.
- Practicalities for a 24-hour Holter
- The recorder and its electrodes must stay dry, so you cannot shower or bathe while wearing it. Tell the team about any adhesive or skin allergy, and keep the symptom diary honestly and by the clock — the report's most valuable line is whether what you felt matched what the trace was doing at that minute.
Who should consider this scan
- Anyone with intermittent palpitations
- People with unexplained dizziness or fainting
- Patients with atrial fibrillation being rate-controlled
- Anyone with a suspected pause or conduction problem
- Patients after a stroke of undetermined cause
Conditions it helps detect
How it works
Patient stories
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