1. Electrical interference

2. Muscle tremor

3. 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.

4. 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
V 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.

6. The result..

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

8. 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

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