EKG normals Flashcards
Which wave shows atrial depolarization?
p wave
which wave shows ventricular depolarization?
QRS
Which wave shows ventricular repolarization?
t wave
What degree is Lead I?
0
What degree is lead II?
+60
What degree is lead III?
+120
what degree is aVL?
-30
what degree is aVR?
-150
What degree is aVF?
+90
How many miliseconds is one box?
5 boxes?
1 box = 40 miliseconds (0.04s)
5 boxes = 200 miliseconds (0.2s)
What happens to the QT interval at a faster HR?
it shortens
what’s a quick way to check if the QT interval is prolonged?
shouldn’t be more than 50% of the way between R-R intervals
(if HR is between 50-100bpm)
What does the Y axis of the EKG represent?
voltage
The Q wave represents depol of ____, the R wave represents depol of ____, and the S wave represents depol of ____.
Q: Bundle of His
R: Bundle branches
S: terminal Perkinje fibers
Where is V1 placed?
4th intercostal space to the R of the sternum
Where is v2 placed?
4th intercostal space to the left of the sternum
Where is v4 placed?
5th intercostal space in midclavicular line
Where is v6 placed?
5th intercostal space in midaxillary line
How many boxes should the p wave be smaller than?
2.5 boxes
how long should the PR interval be?
120-200 ms
How long should the QRS interval be?
80-105 ms
In a normal EKG, where will the QRS complex be inverted?
aVR, V1, V2
What do the R waves look like in the precordial regions of an EKG?
R wave progression - starts almost non-existent at V1, then slowly progresses and is largest at V6
In what direction is the normal axis/vector?
inferiorly toward the left!
