Basic review of 12 lead ecg interpretation

1. 12 Lead Interpretation a
review of the Basics

2. Introduction
 12-Lead Interpretation is easier to read
than normal ECG Interpretation
 Techniques used are performed in
steps
 You can interpret a 12- lead ECG in 60
sec or less.

3. Reading a 12-Lead
 There are 12 Pictures taken of the
heart every time a 12-Lead is taken.
 When looking at the ECG we pick out
only 1 complex in every picture that
represents that picture of the heart.

5. Leads used
 Limb Leads I, II, IIl
 Augmented Limb Leads:
 AVR, AVL, AVF,
 V-Leads or Precordial Leads
If you don’t label the leads, youIf you don’t label the leads, you
don’t know Jack!!!!!!!don’t know Jack!!!!!!!

6. Enthovens triangle
 Triangular
representation of
Leads I,II,II

8. Augmented Voltage leads
 AVR
 AVL
 AVF
 Uses a center ground computer
assisted

10. Precordial Leads
V1-V6

13. Additional Leads

14. V4R
V4R
 5th
intercostal
space mid
clavicular
line

15. V4R
V4R
 Significance of
V4R in relation
to RCA
occulsions vs.
LCA
circumflex
branch
occulsions

18. Things the 12 Lead “sees”

19. Basics of 12 Lead ECG's: Vector

20. Basics of 12 Lead ECG's:Vector

21. Basics of 12 Lead ECG's
Vector
By understanding this concept of vector and
knowing the "normal" vector of each of the 12
leads of the 12 lead ECG it becomes quite easy
to identify problems in the direction of
depolarization. It is also from this knowledge that
one identifies the Mean QRS Axis. Using the six
limb leads we identify the axis in relation to what
is known as the frontal plane. Two major factors
help to determine this mean QRS Axis, they are:
1. The anatomical position of the heart
2. The direction of ventricular depolarization.

22. Basics of 12 Lead ECG's
Determining AXIS
1. Leads 1 and AVF divide
the thorax into quadrants,
(Left, Normal, Right, No
Man's)
2. If leads 1 and AVF are
both upright then the Axis
is normal.
3. If lead 1 is upright and
lead AVF is downward the
Axis is Left.

23. Basics of 12 Lead ECG's
Determining AXIS
4. If lead AVF is upright and lead
1 is downward then the Axis
is Right
5. If both leads are downward
then the Axis is extreme Right
Shoulder and most often is
Vent. Tachy

24. LEAD 1 LEAD 2 LEAD 3
Normal UPRIGHT UPRIGHT UPRIGHT
Physiological
Left Axis
UPRIGHT
UPRIGHT /
BIPHASIC
NEGATIVE
Pathological
Left Axis
UPRIGHT NEGATIVE NEGATIVE
Right Axis NEGATIVE
UPRIGHT
BIPHASIC
NEGATIVE
UPRIGHT
Extreme
Right Axis
NEGATIVE NEGATIVE NEGATIVE

25. Evolution of an AMI

27. Footprints of Posterior MI
 Never runs alone (always with another
MI; Inferior, Lateral, and/or RVI)
 Most of the Posterior Wall supplied by
RCA or LCX
 Look for Tall R wave in V1,V2,V3 with
ST segment depression
 Run Posterior Leads V7,V8,V9

29. ““You see what youYou see what you
look for and onlylook for and only
recognize what yourecognize what you
KNOW”KNOW”

30. Example 1

31. Example 2

32. Example 3

33. Example 4

34. Example 5