Electrocardiogram explained

The heart’s electrical signal coordinates each contraction. An ECG captures that signal as lines and waves, allowing a clinician to examine the timing and pattern of beats. It may help investigate palpitations, fainting, chest discomfort or breathlessness, and can provide clues related to Angina, Atrial Fibrillation or Heart Failure. A result described as normal does not explain every symptom, and an unusual tracing does not by itself establish a final diagnosis.

A standard ECG is recorded while you lie still. Sensors are placed on the skin of the chest and limbs; the test does not put electricity into you. The clinician may compare the tracing with earlier results or recommend another test if symptoms are intermittent.

Wear accessible clothing and avoid body lotion on sensor sites if possible. Tell the operator about skin reactions, implanted devices and any symptoms occurring at the time. Keep still and breathe normally during the recording. Bring your medicine list and ask how the result will be explained. A GP Consultation can help connect the ECG findings with your personal history.

Call emergency services for crushing or persistent chest pain, severe breathlessness, fainting, collapse, or a new fast or irregular heartbeat with weakness or dizziness. Do not wait for a routine ECG appointment when these symptoms are present. If symptoms are mild but recurring, arrange clinical review and keep a note of triggers, duration and associated signs.

Why has an ECG been recommended? What did the tracing show about rate and rhythm? Could symptoms occur when the short test is normal? Do I need repeat testing or longer monitoring, and when should I seek urgent help?