A 12 lead electrocardiography (ECG) shows the electrical activity occurring in a patient’s heart at the moment it is recorded. It is an important diagnostic investigation for arrhythmia’s e.g. atrial fibrillation, or in more serious conditions such as myocardial infarction or in cardiac arrest. It is therefore an essential skill to be able to perform, as well as interpreting the ECG findings.
For this station you will need:
- Hand sanitiser
- ECG machine
- 10 sticky pads for attaching the electrodes to
- Occasionally need wipes and/or razor
Wash your hands and introduce yourself to the patient and clarify their identity.
Explain what you are going to do and gain consent to proceed. Clarify whether the patient knows why the test is being performed e.g. chest pain.
Ensure the patient is comfortable, for this test the patient must have their top off so offer a chaperone.
For the ECG pads to stick there must be good contact with the skin, therefore ensure there is nothing which could prevent this e.g. shave hair or wipe off any cream/lotion.
Input the patients data into the machine correctly, thus ensuring the correct details are printed onto the ECG.
Although this is called a 12 lead ECG you only need 10 sticky pads, 4 for the limb leads and 6 for chest leads. This is where you place them:
- Right wrist (or shoulder)
- Left wrist (or shoulder)
- Right ankle, laterally
- Left ankle, laterally
- V1 in 4th intercostal space at right sternal edge
- V2 in 4th intercostal space at left sternal edge
- V3 between V2 and V4
- V4 in 5th intercostal space in the mid-clavicular line
- V5 horizontal to V4 in anterior axillary line
- V6 horizontal to V4 and V5 in mid-axillary line
Attach the leads to the pads.
The limb leads are coloured: red, yellow, green and black. One way to remember is the order of traffic lights:
- red (R wrist)
- yellow (L wrist)
- green (L ankle)
- black (R ankle)
Note that these colours are used within Europe. America uses a different colour scheme (see: http://en.wikipedia.org/wiki/Electrocardiography).
The chest leads are usually numbered V1-6, attach as shown:
Once all the leads are attached ask the patient to lie as still as possible. Record the reading and print a copy. If the patient had any chest pain at the time of recording you should record this on the ECG.
Disconnect the leads from the pads and allow the patient to remove the pads themselves, or offer assistance if needed. Offer a tissue as the pads are sticky.
Allow the patient to dress and thank them.
An extension to this station could be ECG interpretation; you should therefore be familiar with the most common ECG findings. Typically sinus rhythm, atrial fibrillation (AF), ST elevation (STEMI) are tested, however also knowing what ventricular fibrillation (VF) and ventricular tachycardia (VT) looks like is important for advanced life support skills.