ECG Machine

An ECG machine records the heart's electrical signals through sticky electrodes placed on the skin.

Wires connect the electrodes to the machine, which produces a tracing showing electrical activity from different viewpoints. The test is also called an electrocardiogram. It is a recording test: the electrodes detect signals but do not send electricity into your body.

A clinician places electrodes on the chest and limbs after exposing the required skin. You lie still and breathe normally while the machine captures the tracing. The recording itself is brief, although preparation can take longer if skin needs cleaning or hair needs trimming for the pads to adhere.

Tell the clinician about symptoms you are having, medicines you take, and whether you have a device such as a pacemaker. That context helps the clinician interpret the tracing alongside your history and examination.

An ECG is a snapshot of electrical activity at the time it is recorded. Some rhythm changes come and go, and some heart or chest symptoms need other tests even when an ECG does not show a clear abnormality. The tracing alone does not identify every possible cause of palpitations, breathlessness, dizziness, or chest discomfort.

A clinician may compare the tracing with a previous ECG, arrange longer rhythm monitoring, order blood tests, or consider imaging depending on your symptoms and findings.

Other assessments may include a longer wearable rhythm recording, blood tests, an echocardiogram, or exercise-related testing. These are chosen for a specific clinical question; they are not direct replacements for each other. Your clinician will explain which test fits the symptoms being investigated.

A normal or abnormal tracing needs to be interpreted with your symptoms, medical history, examination, and sometimes previous results. Ask what the ECG showed, whether follow-up is needed, and what symptoms should prompt earlier contact. Keep a note of episodes such as racing heartbeat, dizziness, or discomfort, including what you were doing when they began.

Call emergency services for chest pressure or pain that is severe, persistent, or accompanied by breathlessness, sweating, fainting, nausea, or pain spreading to the arm, jaw, back, or shoulder. Do not wait for a routine ECG appointment if these symptoms are happening now. New fainting, severe breathlessness, or a sustained fast or irregular heartbeat with feeling unwell also needs urgent assessment.