USMLE Forums banner
1 - 5 of 5 Posts

·
Registered
Joined
·
21 Posts
Discussion Starter · #1 ·
Hi guys

I didn't understand anything in Einthoven's triangle and the basis of Axis Deviation:confused::scared:


and what is this I + III = II ?


Any inputs are welcome :)
 

·
Registered
Joined
·
242 Posts
Hi guys

I didn't understand anything in Einthoven's triangle and the basis of Axis Deviation:confused::scared:

and what is this I + III = II ?

Any inputs are welcome :)


Even before you start reading I assume that you understand basic concepts on vectors,if so read on

Look at the pic, you will see

I: RA to LA
II: RA to LF
III: LA to LF

RA: right arm, LF: left foot

also mark the arrows that the I arrow is directed from RA to LA and so on...

By the rule of vectors in a triangle if we add all the three sides of the triangle in either clockwise or anticlockwise fashion they give us a total of zero,so

side1 + side2 + side3 = 0

but in this picture note II(side2) is not clockwise, its just the reverse ie for it to be clockwise it should had run from LF to RA instead it is RA to LF, so - II is same as clockwise, so we can write

side1 + side2 + side3 = 0

=> I + III + (-II) = 0
=> I + III = II

I hope its clear...and coming to axis deviation;try this site
Code:
http://ecg.utah.edu/lesson/2-1
although I dont know how much high yield axis deviation is Happy-2

:cool:
 

·
Registered
Joined
·
66 Posts
I always use the quick and dirty method for determining axis that I learned from an anesthesia attending. Here's what you do:

1) Look at EKG
2) Put both of your fists in front of you and make two "thumbs up" signs
3) Think of your left thumb as Lead I and your right thumb as aVF
4) Look at the QRS complex in I and aVF on the EKG
5) Point your respective thumb in the direction of the respective QRS

Both thumbs up = normal axis
Left up/right down = left axis deviation
Right up/left down = Right axis deviation
Both down = lead misplacement, try again

This method is accurate ~95% of the time :)
 

·
Registered
Joined
·
76 Posts
I always use the quick and dirty method for determining axis that I learned from an anesthesia attending. Here's what you do:

1) Look at EKG
2) Put both of your fists in front of you and make two "thumbs up" signs
3) Think of your left thumb as Lead I and your right thumb as aVF
4) Look at the QRS complex in I and aVF on the EKG
5) Point your respective thumb in the direction of the respective QRS

Both thumbs up = normal axis
Left up/right down = left axis deviation
Right up/left down = Right axis deviation
Both down = lead misplacement, try again

This method is accurate ~95% of the time :)
Wow !
Impressive indeed !!!
A helpful trick I just discovered Happy-2

Thank you !
 

·
Registered
Joined
·
242 Posts
I always use the quick and dirty method for determining axis that I learned from an anesthesia attending. Here's what you do:

1) Look at EKG
2) Put both of your fists in front of you and make two "thumbs up" signs
3) Think of your left thumb as Lead I and your right thumb as aVF
4) Look at the QRS complex in I and aVF on the EKG
5) Point your respective thumb in the direction of the respective QRS

Both thumbs up = normal axis
Left up/right down = left axis deviation
Right up/left down = Right axis deviation
Both down = lead misplacement, try again

This method is accurate ~95% of the time :)
Hey it actually worked thanks a bunch...bookmarked this now,anyone can try the following:

BOTH UP in this one:


LEFT UP, Right Down in this one:


RIGHT UP, Left Down in this one:


I just tried your technique on this and it worked just fine thanks a lot :D
 
1 - 5 of 5 Posts
Top