The ECG Flashcards
How does an ECG work?
Potential differences between distant sites on the Body surface measurable by electrodes placed on the skin coupled to a sensitive recording device (ECG)
What are the 3 standard limb leads?
Lead 1 : Right arm (RA) -ve to Left arm (LA)+ve
Lead 2: RA-ve - LL+ve
Lead 3 : LA-ve - LL+ve
What are the 3 augmented limb leads?
- augmented voltage right
- augmented voltage left
- augmented voltage foot
How many chest leads are there ?
6
How do you calculate heart rate?
300/number of large squares between beats
What is the ECG Rhythm strip?
-prolonged recording of one lead (usually standard limb lead 2) - this allows you to detect rhythm disturbance
Where is the rhythm strip on the paper?
Bottom of the page
Why are 12 leads needed?
- Determine the axis of the heart in thorax
- Look for any ST segment or T wave changes in relation to specific regions of the heart. This is curtail e.g. in diagnosing Ischaemic Heart Disease
- Look for any voltage criteria changes. This is curtail e.g. in diagnosing chamber hypertrophy
What 3 significant disease cannot be identified by a resting ECG?
- myocardial infarction
- intermittent rhythm disturbance
- stable angina