12-Lead ECG Placement Flashcards

Comprehensive practice flashcards covering standard 12-lead ECG electrode placement, anatomical landmarks, procedural order, memory cues, and common placement errors.

How many electrodes make up a standard 12-lead ECG?

10 electrodes: 4 limb electrodes and 6 chest (precordial) electrodes. They generate 12 electrical views.

Where is V1 placed?

4th intercostal space (ICS), right sternal border.

Where is V2 placed?

4th intercostal space (ICS), left sternal border.

Where is V3 placed?

Halfway between V2 and V4.

Where is V4 placed?

5th intercostal space, left midclavicular line.

Where is V5 placed?

Same horizontal level as V4, at the left anterior axillary line.

Where is V6 placed?

Same horizontal level as V4 and V5, at the left midaxillary line.

Which chest leads sit at the 4th intercostal space?

V1 and V2.

Which chest lead is at the 5th intercostal space?

V4.

How do you find the 4th intercostal space?

Locate the sternal angle (Angle of Louis), identify the 2nd rib/2nd intercostal space, then count down to the 4th intercostal space.

What is the recommended order for placing the chest leads?

Place V1 and V2; locate and place V4; place V3 halfway between V2 and V4; then place V5 and V6 level with V4.

Why should V4 be located before V3?

V3 is positioned halfway between V2 and V4, so V4 must be identified first.

Should V4, V5 and V6 be horizontally aligned?

Yes. V5 and V6 should be on the same horizontal level as V4.

Where is V5 in relation to V4?

At the same horizontal level, on the left anterior axillary line.

Where is V6 in relation to V4 and V5?

At the same horizontal level, on the left midaxillary line.

What does RA mean and where is it placed?

Right arm electrode; on the right arm/wrist or an approved consistent upper-torso position.

What does LA mean and where is it placed?

Left arm electrode; on the left arm/wrist or an approved position matching RA.

What does RL mean and where is it placed?

Right leg electrode; on the right lower limb/ankle or approved lower-torso position. It is the reference/ground electrode.

What does LL mean and where is it placed?

Left leg electrode; on the left lower limb/ankle or approved position matching RL.

What are the four limb electrodes?

RA (right arm), LA (left arm), RL (right leg) and LL (left leg).

What is a common V1/V2 placement error?

Placing them too high, instead of in the 4th intercostal space.

Why does incorrect V1/V2 placement matter?

It can alter the ECG appearance and contribute to misleading interpretation.

What is a common V5/V6 placement error?

Placing them too high or low instead of keeping them horizontally level with V4.

Should V5 be placed between V4 and V6?

It is anatomically between V4 and V6, but the precise landmark is the left anterior axillary line, level with V4.

Should the chest leads follow the curve of the ribs?

No. V4, V5 and V6 should be kept on the same horizontal level.

What should you do before applying ECG electrodes?

Explain the procedure, obtain consent, preserve privacy, prepare the skin and ensure good electrode contact.

Where should V4 be placed if breast tissue overlies the landmark?

With consent and appropriate draping, place it on the chest wall at the correct anatomical landmark, beneath the breast tissue where appropriate.

What should you check if the ECG has excessive artefact?

Electrode adhesion and skin contact, patient movement/shivering, cable connections and electrical interference.

What is the V1 memory cue?

4th ICS, right sternal border.

What is the V2 memory cue?

4th ICS, left sternal border.

What is the V3 memory cue?

Halfway between V2 and V4.

What is the V4 memory cue?

5th ICS, left midclavicular line.

What is the V5 memory cue?

Level with V4, left anterior axillary line.

What is the V6 memory cue?

Level with V4/V5, left midaxillary line.

Which lead is at the left anterior axillary line?

V5.

Which lead is at the left midaxillary line?

V6.

A student places V1 in the 3rd intercostal space. Correct?

No. V1 belongs in the 4th intercostal space at the right sternal border.

A student places V5 lower than V4. Correct?

No. V5 must be horizontally level with V4 at the left anterior axillary line.

What is the fastest way to remember V1 and V2?

Both are in the 4th intercostal space: V1 right of sternum, V2 left of sternum.

What is the fastest way to remember V4–V6?

V4 = midclavicular; V5 = anterior axillary; V6 = midaxillary. Keep all three level.

What should be documented regarding modified torso placement of limb electrodes?

Modified torso placement can change the ECG and should be documented.