electrical axis and blocks Flashcards
mean QRS between what two degrees
0 and 90
anything between 90 - 90 will be + on what limb lead
one
If the mean QRS is between 0 - 180 it will be + in what augmented lead
AVF
left axis deviation is an example of what
Lead I: +
AVF: -
Right axis deviation can be seen if what
Lead I: -
AVF: +
EVERY cycle has a P wave, followed by a QRS complex, followed by a T wave. This is called what
NSR Normal sinus rhythm
Normal PR interval
3-5 small boxes
normal QRS length
<3 small boxes
NR rate
60-100
5 steps to EKG
- Regularity
Assess the regularity of the rhythm – are the cardiac cycles equal? - Rate
Calculate the ventricular rate (R to R) - P waves
Evaluate shape, size and rate (P to P) → is there a P wave before every QRS complex? - PR intervals
Normal 0.12 – 0.20 sec, 3-5 small boxes
PT interval should be constant → Does the PR interval change? - QRS complexes
Normal <0.12 sec, 3 small boxes → are the complexes narrow or wide?
Sinus pause is also called
Sinus arrest
during sinus pause what happens
no electrical impulse out of the SA node, skips a beat
how long is ok for SA pause
< 2 seconds
> 6 Concerning
sinus pause
drop a QRS > 1 beat
sinus block
Drop of 1 QRS Sa node is firing it’s just not getting out
what AV heart block is mostly a delay
1st degree
What AV block is a Wenckebach
2nd degree type 1
what AV block is a Mobitz
2nd degree type II
what AV block is a complete heart block
III degree
What AV block consists of a long PR interval that is consistent
1st degree
Impulses arise from the SA node but their passage through the AV node is delayed
1st degree
the PR interval increases with each heart beat until it is so long that the signal doesn’t reach the ventricles and the depolarization is “blocked” at the AV node
Wenckebach (2nd degree type I )
the rhythm would be regularly irregular
P waves are randomly blocked just below the AV node.
2nd degree type II
what AV block can progress to type to type III
2nd degree type II
There is dissociation of electrical acticity betwee the artria and ventricles nothing is passing from SA to the AV node
third degree heart block
