All procedures
GMC #10/Diagnostic procedures taught Y1
3- and 12-lead electrocardiogram
Set up a recording of the electrical activity of the heart, ensuring all leads are correctly placed.
Target · Perform independently0% ready
Do it yourself on a patient, with support available if you need it — the GMC’s highest new-grad level (“indirect supervision”).
Overview
Correct lead placement is a patient-safety issue — misplacement mimics or masks ischaemia. Know the chest-lead landmarks cold.
Key numbers
- Standard calibration: paper speed 25 mm/s, amplitude 10 mm/mV (1 large square = 0.2 s)Resus Council UK / SCST
- V1 = 4th ICS right sternal edge · V2 = 4th ICS left sternal edge · V4 = 5th ICS mid-clavicular line · V6 = mid-axillary, level with V4SCST lead placement
Indications
- Chest pain, palpitations, syncope, breathlessness
- Suspected ACS/arrhythmia; pre-op; electrolyte/drug effects
Equipment
ECG machine + fresh electrodesRazor & wipes (skin prep)
Step by step
Prepare
- 1Confirm identity; expose the chest, wrists, ankles; position semi-recumbent
- 2Clean/shave skin for good contact
Place leads
- 1Limb leads: Red→Right arm, yeLLow→Left arm, Green→left leg (foot), blacK→right leg (“Ride Your Green Bike”)
- 2V1: 4th intercostal space, right sternal edge
- 3V2: 4th ICS, left sternal edge
- 4V4: 5th ICS, mid-clavicular line
- 5V3: midway between V2 and V4
- 6V5: anterior axillary line, same horizontal as V4
- 7V6: mid-axillary line, same horizontal as V4
Record
- 1Check calibration (25 mm/s, 10 mm/mV); minimise artefact
- 2Print; label with name, DOB, date/time and whether symptomatic
- 3Interpret systematically: rate, rhythm, axis, P-QRS-T, intervals, ischaemia
Complications
- Misplaced leads → misdiagnosis; skin irritation
OSCE tips
- Lead placement is the marked skill — recite the V1–V6 landmarks.
- Always label the trace (name/DOB/time/symptoms).
- State the calibration and read systematically.
Read
Sources & credits
Authored to UK finals standard and verified against UK guidance (Resus Council UK · SCST lead placement) and Geeky Medics OSCE guides . Southampton teaching materials © University of Southampton. Always follow current local policy.