What is your system to reading ECGs? (8)
How many mm/s is a whole strip?
25 mm/s
how many m/s and s is 1 large square?
0.2s or 200ms
How many m/s or s is 1 small square?
0.04 s or 40ms
Where do you start reading the PR interval from?
the beginning of the p wave to the beginning of the q wave
How long should the PR interval be?
120-220 ms
What is standard rates?
R-R interval Heart rate (bpm)
1 300
2 150
3 100
4 75
5 60
6 50
What do leads I, II and VL look at?
left lateral surface of the heart
What do leads III and VF look at?
the inferior surface
What does lead VR look at?
right atrium
Where do leads V1-6 look at the heart?
they look at the heart from the horizontal plane
Rhythm strip - what is it
whichever lead shows the p wave most clearly usually lead II
What are the deflection in VR and II usually?
VR - downwards
II - upwards
What deflection are leads I, II and III associated with and why?
upwards deflection
what is right axis deviation?
deflection in lead I becomes negative
deflection in lead III become more positive
right ventricle becomes hypertrophied
normal axis
lead I, II and III all positive deflections
lead II with most positive deflection
left axis deviation
lead I - small positive deflection
lead II - negative deflection
lead III - negative deflection
left ventricle is hypertrophied
What is first degree heart block?
PR interval is prolonged
What is second degree heart block?
excitation completely fails to pass through the AV node or bundle of His.
This occurs intermittently
What is seen in Mobitz type I/ Wenebach second degree heart block?
What is seen in Mobitz type II?
What is third degree heart block?
this is complete heart block
What is right bundle branch block?
think Marrow
Left bundle branch blcok
Willaim