Welch Allyn Means ECG Physicians Manual for CP Series Electrocardiographs - User Manual - Manual (Page 15)

MEANS Physicians Manual
Welch Allyn
15
2.10 Axis deviations and fascicular blocks
Axis deviations are distinguished in vertical, right, marked right and extreme right inferior on
the one hand and horizontal, left, marked left and extreme right superior on the other hand.
Besides a complete LBBB it is also possible to find a left anterior or posterior fascicular block
(LAFB or LPFB). These statements will always be tested in combination with an axis
deviation. (LPFB can only be diagnosed in conjunction with RBBB.)
In the presence of inferior infarction no statement of left axis deviation is given, it being due to
initial negativity in the inferior leads. In the presence of LBBB the axis tends to deviate to the
left. Therefore the threshold for stating left axis deviation is increased. Moreover, the
diagnosis of complete LBBB takes precedence over that of left anterior fascicular block.
Say: “vertical axis”
if: 80 < QRS axis

100

Say:
“right axis deviation”
if: 100 < QRS axis

120

Say:
“marked right axis deviation”
if: 120 < QRS axis

150

Say:
“extreme right inferior axis deviation”
if: 150 < QRS axis

180

Say:
“consistent with LPFB”
if: 120 < QRS axis

180

and RBBB
Say:
“horizontal axis”
if:

30

QRS axis <

10

if:
test LBBB did not pass
then:
Say: “left axis deviation”
if:

60

QRS axis <

30

Say: “marked left axis deviation”
if:

120

QRS axis <

60

Say: “extreme right superior axis deviation”
if:

180

QRS axis <

120

Say: “consistent with LAFB”
if:

120

QRS axis <

45

and S amplitude in III > 500 µV
and S amplitude in III < S amplitude in II
if:
test LBBB passed
then:
Say: “left axis deviation”
if:  120  QRS axis <  45
