LECTURE: Vectors & Electrodes

3-Electrode System

• 3 electrodes: R-arm, L-arm, L-leg
• Monitors bipolar leads (I, II, III)
• Best results if electrodes placed on chest wall equidistant from heart (rather than specific limbs)

5-Electrode System

• 5 electrodes: R-arm, R-leg, L-arm, L-leg, chest
• Monitors bipolar leads (I, II, III) & unipolar lead (depending on brown chest lead position, V1-V6)

10-Electrode System (12-Lead ECG)

• 10 electrodes:
• 4 on all limbs (R-arm/leg, L-arm/leg)
• 6 electrodes on precordium (V1-V6)
• Monitors 12 leads (I, II, III, aVR, aVF, aVL, V1-V6)
• Allows interpretation of specific areas of heart: inferior (II, III, aVF), lateral (I, aVL, V5-V6), anterior (V1-V4)

Abbreviations: R, right; L, left