ECG (Electrocardiogram)
A focused scan for Heart rhythm, Heart rate, Arrhythmia and more.
Overview
Examines Heart rhythm, Heart rate, Arrhythmia, Ischaemia. Performed at an NABL-accredited Meridian Health centre with a same-day report and a free doctor review.
The full panel
4 areas across 1 groupEvery parameter, grouped by body system — no clicking to expand.
What this scan measures
The heart's electrical activity, recorded from ten electrodes on the chest and limbs to produce twelve different views. It shows the rate, the rhythm, the path the electrical impulse takes through the heart, and the electrical signature of muscle that is thickened, strained or short of blood.
The ECG is the immediate test in chest pain, palpitations and fainting because it can be done in under a minute anywhere, and it is the first thing that changes in an evolving heart attack. It is also standard before surgery, in hypertension and diabetes reviews, and before starting drugs that affect cardiac conduction.
Symptoms that lead to this scan
- Chest pain, pressure or tightness — seek emergency care if severe or ongoing
- Palpitations or an irregular pulse
- Fainting, near-fainting or unexplained dizziness
- Breathlessness on exertion
- Pre-operative assessment, or routine review with known heart risk
Understanding your results
An ECG is a snapshot of a few seconds. A completely normal ECG does NOT exclude coronary artery disease — it is common for the resting trace to be normal in someone with significant narrowing, which is exactly why treadmill testing, echocardiography and CT angiography exist. Equally, some abnormal-looking patterns are benign normal variants. Intermittent rhythm problems are frequently missed on a 10-second recording and are the reason a Holter monitor is used. If you are having chest pain now, an ECG report is not a substitute for emergency assessment.
Indicative only. Reference ranges vary between laboratories and between testing methods, and shift with age, sex and pregnancy — always read your own result against the range printed on your own report, with the doctor who ordered it.
| Parameter | Indicative range | Unit |
|---|---|---|
| Resting heart rate | 60–100 | beats/min |
| PR interval | 120–200 | ms |
| QRS duration | Below 120 | ms |
| Corrected QT (QTc) | Below 440 (men) · below 460 (women) | ms |
Why the preparation matters
No preparation and no fasting. Avoid applying moisturiser or oil to the chest on the day, because the electrodes need clean skin contact and a poor contact produces a noisy trace that can mimic an abnormality. Chest hair may need trimming at the electrode sites. Rest quietly for a few minutes before the recording and stay still and relaxed during it — shivering and muscle tension create artefact that looks like an arrhythmia.
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 chest pain, palpitations or fainting
- Adults with hypertension, diabetes or high cholesterol at review
- Anyone due for surgery or an anaesthetic
- People starting medication that affects heart rhythm
- Anyone with a family history of sudden cardiac death
Conditions it helps detect
How it works
Patient stories
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