Intro to EKG Flashcards
What is the normal axis for an EKG?
-30 to +90
How many seconds are in one small box on EKG?
40 ms
How many seconds are in one big box EKG?
200 ms
How can you determine HR for normal rhythm?
count the number of big boxes between 2 RR waves
divide 300 by # of big boxes
How can you determine HR for irregular rhythm?
count the number of QRS complexes on bottom strip and multiply by 6
we were multiplying by 6 in class
What are limits for tachycardia and bradycardia?
Tachy : >100 bpm
Brady : < 60 bpm
If lead I is positive and lead aVF is positive, what is your axis?
0 - +90º (normal)
(remember that positive 90 is downwards for lead aVF)
If lead I is positive and lead aVF is negative, what is your axis?
axis between (-) 30º - (-) 90º
this is a left shift!
If lead I is negative and lead aVF is positive, what is your axis?
axis between +90º - +180º
this is a right shift
How big is PR interval normally?
normally 1 big box
120-200 ms
How big is QRS duration normally?
normally < 3 small boxes
< 120 ms
How long is QT interval normally?
T wave is < halfway between RR interval
QT should be < 440 ms
How can you determine if there is a ST segment elevation or depression?
compare to PR line for reference
Which leads are left sided?
leads 4-6
Which leads are right sided?
leads 1-3
What are the lateral leads?
I, aVL, V5-V6
What do the lateral leads give us information about?
LCx or diagonal of LAD
What are the inferior leads?
II, III and aVF