Investigations Flashcards
In an ECG, what does the P wave represent?
Atrial depolarization
In an ECG, what does the QRS complex represent?
Ventricular depolarization
How is ventricular repolarisation represented in an ECG?
The T wave
How is AV nodal delay represented in an ECG?
PR interval
What does the ST segment represent in an ECG?
Ventricular systole
What does the TP interval represent in an ECG?
Diastole
How long is the P wave normally?
0.08 - 0.1 seconds
How long is the QRS complex normally?
< 0.1 seconds
How long is the PR interval normally?
0.12 - 0.2 seconds
In an ECG, what does a small square represent (with regards to time)?
0.04 seconds
In an ECG, what does a large square represent (with regards to time)?
0.2 seconds
How do you calculate heart rate from an ECG?
300/number of large squares between beats OR 300/number of large squares between R-R interval
What is the ECG rhythm strip? (at the bottom of an ECG paper)
A prolonged reading of one lead (usually lead 2) - allows you to detect rhythm disturbances
First question you should ask when looking at an ECG?
Is the patients information correct?
Where do you put chest lead one (V1)?
4th intercostal space, right sternal edge
Where do you put chest lead two (V2)?
4th intercostal space, left sternal edge
Where do you put chest lead 3 (V3)?
Midway between V2 and V4
Where do you put chest lead 4 (V4)?
Fifth intercostal space, left midclavicular line
Where do you put chest lead five (V5)?
Level with V4, left anterior axillary line
Where do you put chest lead 6 (V6)?
Level with V4, left mid axillary line
