Electrical interference

Muscle tremor

Limb leads 4 leads on the limbs (right and left wrists and right and left ankles) Right ankle acts as ground lead-doesn’t form a trace Need these 4 leads to have an ECG Form Einthoven's triangle and the augmented limb leads Leads I, II, III, aVR, aVF and aVR produces zero potential when the voltages are summed.

Chest leads 6 unipolar leads placed across the chest: V1, V2, V3, V4, V5 & V6 Extra care needed with placement of the leads as incorrect placement can result in inaccurate interpretation!! V1 4th intercostal space, right of sternum V2 4th intercostal space, left of sternum V3 halfway between V2 and V4 V4 5th intercostal space , midclavicular line V5 Same horizontal position as V4, anterior axillary line V6 Same horizontal position of V4, midaxillary line.

The result..

Interpreting an ECG Heart rate Regularity Rhythm Morphology of complexes Duration of complexes Intervals ST segments

Heart rate 11 complexes times 6 = 66bpm We need to be able to calculate the number of QRS complexes in one minute ECG is recorded over 10 seconds therefore you can multiply the number of complexes on a strip by 6 to give you the rate per minute Use the Rhythm strip at the bottom 11 complexes times 6 = 66bpm

Heart rate Normal resting HR 60- 100 bpm >100bpm: Tachycardia < 60 bpm: Bradycardia