ECG basics Flashcards
what does the time of one small square equal? what about a large square? how many large squares to get a second?
small square is 0.04
large is 0.2
5 large squares make a second
where does lead I run from?degree
from right arm to left arm
0
where does lead II run from? degree
from right arm to left leg
60
where does lead III run from? degree
from left arm to left leg
120
where does aVl run from? degree
from the heart to the left arm
-30/150
where does aVr run from? degree
from the heart to the right arm
-150/30
where does aVf run from? degree
heart to the foot
90/-90
what are the two leads you use to figure out the quadrant? and what is the last step?
aVf and lead I
once you know quadrant…look for most isoelectric lead and draw perpendicular line
Where are V1 and V2 leads located?
in left and right 4th intercostal spaces
where is V4 lead?
in the 5th intercostal space, just to patients left of sternal border
where is V3 lead?
between V2 and V4 on the way from the 4th intercostal and 5th intercostal
where is V6 located?
midaxillary in the 5th intercostal space
where is V5 located?
between V4 and V6 in the 5th intercostal space
name the three segments of an ECG
PR segment
QRS segment
QT segment
what is the PR segment?
from start of atrial depol to start of ventricular depol
what is QRS segment?
All of ventricular depol
what is the QT segment?
ventricular depol and repol (end of T)
what are the two septal leads?
V1 and V2
what are the two lateral leads?
V5 and V6
what are the two anterior leads?
V3 and V4
what lead do you check to make sure the P wave is upright?
lead II
3 steps for checking rhythm on ECG
- make sure p wave followed by QRS
- look at lead II to see P wave upright
- regular rhythm
if you have a beat within 1 big box..whats the heart rate?
300 BPM
if you have a beat within 2 big boxes…whats the heart rate?
150 BPM
if you have a beat within 3 bix boxes whats the heart rate?
100 BPM
if you have a beat within 4 big boxes, whats the heart rate?
75 BPM
if you have a beat within 5 big boxes whats the heart rate?
60 BPM
if you have a beat within 6 big boxes whats the heart rate?
50 BPM
what is the normal length of the PR interval?
0.12 to 0.2 seconds
if the PR interval is short, what do we suspect?
accessory pathway increasing rate
if the PR interval is long, what do we suspect?
AV block
what is the normal length of the QRS interval?
0.08 to 0.12
if the QRS is lengthened what do we suspect?
a bundle branch block or ventricular rhythm
what is the normal length of the QT interval?
0.45 to 0.5
what do we suspect if the QT interval is lengthened?
torsagus
