Electronic ECG machine: what to know

An ECG machine receives signals from adhesive electrodes placed on the chest and limbs. The result is a tracing of electrical activity across the heartbeat. It can help a clinician assess rhythm, heart rate, conduction changes and patterns that may accompany chest symptoms. A standard recording captures only the time of the test, so an intermittent problem may not appear during that brief window. The machine records data; a trained clinician interprets it.

Wear clothing that allows access to the chest and limbs, and tell the clinician about medicines, implanted devices and symptoms. During the recording, lie still, relax your muscles and breathe normally unless instructed otherwise. The electrodes may feel cool when applied and may tug slightly when removed. Ask how you will receive the result and whether you need follow-up testing. Learn more about the [ECG Machine](/technology/ecg-machine/) and [Electrocardiogram](/treatments/diagnostics-and-screening/ecg/).

An ECG is a test, not a reason to postpone emergency care. Call emergency services for new chest pressure, severe breathlessness, fainting, sudden weakness, or a sustained racing heartbeat, especially when symptoms are severe or worsening. Arrange a clinical review for repeated palpitations, unexplained dizziness or reduced exercise tolerance, even if a previous tracing was normal.

What question is this ECG intended to answer? Could an intermittent symptom require longer monitoring? When and how will the tracing be explained to me?