What should you know about an ECG heart test machine?

An ECG uses adhesive electrodes on the chest and limbs to sense electrical changes associated with each heartbeat. Wires carry those signals to the machine, which prints or displays a tracing. A clinician reviews the pattern for information about heart rate, rhythm, and certain changes that may require more assessment.

The machine records a short window in time, so a normal tracing may not explain symptoms that come and go. Depending on your history, a clinician may discuss monitoring over a longer period or another test. Results should be interpreted with your symptoms, examination, medicines, and medical history.

Wear clothing that allows access to the chest, arms, and lower legs. Before the recording, mention medicines, a pacemaker, skin irritation, or trouble lying flat. Lie quietly, breathe normally, and avoid speaking while the tracing is collected. Shivering, tense muscles, movement, or a loose electrode can add artefact and may lead to a repeat recording.

The test itself is external and does not inject medicine or send a shock. Once the electrodes are removed, you can usually return to your normal activities unless your clinician gives different advice.

Call emergency services for ongoing chest pain or pressure, severe breathlessness, collapse, or fainting, particularly when symptoms occur with sweating, nausea, unusual weakness, or pain spreading to the jaw, back, or arm. An ECG appointment is not a substitute for emergency care. Seek prompt review for new or recurrent racing, fluttering, or irregular heartbeat, especially with dizziness.

Ask what question the ECG is intended to answer, whether your symptoms should be recorded during an episode, who will review the tracing, and what follow-up is planned. Ask how quickly to seek help if symptoms return before the result is available.