ECG Procedure Instruction

1. PURPOSE An ECG is used to measure the heart’s electrical conduction system. It picks up electrical impulses generated by the polarization and depolarization of cardiac tissue and translates into a waveform. The waveform is then used to measure the rate and regularity of heartbeats, as well as the size and position of the chambers and the presence of any damage to the heart 3. PROCEDURE 3.1 Subject Preparation 3.1.1 Explain full procedure to subject. 3.1.2 Ask the subject to remove or loosen upper body clothing, any wrist jewellery shoes and socks. The subject must lie flat for a minimum of 10 minutes prior to taking the ECG. 3.1.3 Ensure adequate supply of disposable tab electrodes. 3.1.4 Skin preparation equipment, if required, helps to produce an artefact free and accurate ECG, remove any chest hair or cleanse skin if required. 3.1.5 Electrode placement, each limb lead is generally colour coded to aid identification. Attach limb leads to both arms and legs, slightly proximal to the wrist and ankle.  Right arm limb lead (RA, (R) Red) – Right forearm, proximal to wrist  Left arm limb lead (LA, (L) yellow) – left forearm, proximal to wrist  Left leg limb lead (LL, (F) green) – left lower leg, proximal to ankle  Right leg limb lead (RL, (N) black) – Right lower leg, proximal to ankle 3.1.6 The correct anatomical position for the precordial leads have been defined and should always be used. Electrode Position Page 2 of 5 V1 (C1) Fourth intercostal space at the right sternal edge V2 (C2) Fourth intercostal space at the left sternal edge V3 (C3) Midway between V2 and V4 V4 (C4) Fifth intercostal space in the mid-clavicular line V5 (C5) Left anterior axillary line at the same horizontal line level as V4 V6 (C6) Left mid-axillary line at the same horizontal level as V4 &V5 3.1.7 Care should be taken when counting the intercostal spaces down from the clavicle so that the small space between the clavicle and the first rib is not mistaken for the intercostal space. 3.1.8 Once the leads are attached instruct the volunteer to breath normally, ensure the patient is relaxed and still. Page 3 of 5 3.1.9 Press the appropriate button on the machine to initiate recording (usually labelled ‘record ECG’ or ‘START’). A 12–lead ECG and rhythm strip should be recorded at 25mm/s with a gain setting of 10mm/mV 3.2 Machine Set up 3.2.1 Ensure the power cable is connected to the ECG machine and switched on at the wall 3.2.2 Enter patient details: Enter subject’s name or study identification as per protocol Enter Patients DOB Enter ‘Male’ or ‘Female’ 3.2.3 Press Enter 3.2.4 Record ECG 3.2.5 The ECG must be reviewed, signed and dated by the study doctor or appropriate physician. Review for:  A PR interval of >220  A QRS interval of >120ms  A QTC of >440ms must be reported immediately  Check any study specific exclusions 4. 3.2.6 Remove all leads. Cleanse the skin with tissue to remove any remaining gel residue from the tab electrodes. 3.2.7 Place a copy of the signed and dated ECG in the patients screen file. RELEVANT DOCUMENTS The Society for Cardiological Science &Technology, Clinical Guidelines by consensus, Recording a standard 12-lead electrocardiogram, An Approved Methodology, British Cardiovascular Society, February 2010 https://www.bcs.com/documents/consensus_guidelines.pdf Page 4 of 5