ECGs Flashcards
lead colour and where does it get stuck to: V1
red
4th IC space R sternal edge
lead colour and where does it get stuck to: V2
yellow
4th IC space L sternal edge
lead colour and where does it get stuck to: V3
green
midway between V2 and V4
lead colour and where does it get stuck to: V4
brown
5th IC space midclavicular line
lead colour and where does it get stuck to: V5
black
left anterior axillary line, same level V4
lead colour and where does it get stuck to: V6
mauve
left mid axillary line, same level V4 and V5
red limb lead
right ulnar styloid process
yellow limb lead
left ulnar styloid process
green limb lead
left medial malleolus
black limb lead
right medial malleolus
what do 5 large squares =
one second
what does 1 large large square =
0.2s
what does 1 little square =
0.04s
what does P wave correspond to
atrial depolarisation
what does QRS complex correspond to
ventricular depolarisation
what does T wave correspond to
ventricular repolarisation
PR interval
time from atrial depolarisation to ventricular depolarisation
should be 0.12-0.2s (3-5 little squares)
QRS complex
time for whole of ventricle to depolarise
should be <0.12s (< 3 little squares)
QT interval
time spent in ventricular depolarisation and repolarisation
should be max 0.42s
ARI BAR
any electrical activity? rate irregular or regular broad or narrow QRS complexes atrial activity relationship between P waves and QRS complexes
calculating ventricular rate
count number of QRS complexes in 30 big squares.
times the number by 10
determining whether or not QRS complexes are irregular or regular
mark 3 on bit paper and slide paper along to check the next 3 line up
is QRS complex broad or narrow
3 or less little squares
if so then means impulse was initiated and atrioventricular node = normal
broad QRS complexes
> 3 little squares (>0.12s)
impulse has arisen from ventricles - not depolarised normally
checking for atrial activity and relationship between P waves and QRS complexes
are there P waves?
is there a P wave before each QRS and a QRS after each P wave
PR interval - should be 3-5 little squares
1st degree heart block
prolonged PR interval (>5 small squares)
2nd degree heart block
there is a relationship between P and QRS but is variable
3rd degree heart block
no relationship between P and QRS
