Performing a 12 lead ECG

Performing a 12-Lead ECG

A 12-lead Electrocardiogram (ECG) is a vital diagnostic tool used to assess the electrical activity of the heart. This guide provides essential steps and considerations when performing a 12-lead ECG in the United Kingdom.

Preparation

Before starting, ensure the patient is relaxed and lying down, preferably on an examination couch or bed. Ask them to remove any jewellery or clothing on the upper torso. Clean the skin where electrodes will be placed to ensure a good electrical connection, using alcohol wipes if necessary.

Electrode Placement

Accurate placement of electrodes is critical for obtaining reliable results. The standard 12-lead ECG requires ten electrodes to be placed on the body as follows:

• Four limb electrodes: one on each arm and leg, usually on the wrists and ankles.
• Six chest electrodes: positioned on the chest in specific locations (V1 to V6).

Here is a brief guideline for chest electrode placement:

• V1: Fourth intercostal space, right sternal border.
• V2: Fourth intercostal space, left sternal border.
• V3: Midway between V2 and V4.
• V4: Fifth intercostal space, mid-clavicular line.
• V5: Horizontal to V4, anterior axillary line.
• V6: Horizontal to V4, mid-axillary line.

Recording the 12-Lead ECG

After connecting the electrodes, ensure all cables are securely attached to the ECG machine. Explain to the patient that they need to remain still and breathe normally during the recording to avoid any artefacts. Press the start button on the machine to begin recording.

Review and Interpretation

Once the recording is complete, review the tracings for clarity and identify any artifacts. Familiarise yourself with the normal ranges of the heart's electrical activity to interpret the results effectively. In the UK, it is common practice for a trained technician or healthcare professional to perform the initial interpretation before passing it on to a specialist if needed.

Patient Aftercare

After the ECG procedure, help the patient remove the electrodes and allow them to dress. Provide reassurance and explain the next steps if any follow-up is required. Ensure they understand if they need to wait for results or if they will be contacted later.

Performing a 12-lead ECG correctly is essential to providing accurate diagnostics for cardiac conditions. Proper preparation, accurate electrode placement, and clear communication with the patient can significantly impact the reliability of the ECG results.