Download presentation

Presentation is loading. Please wait.

Published byLia Bristol Modified over 2 years ago

1
Determining The Hearts Electrical Axis

2
Principles To Remember l Principle # 1 : When a positive sensing electrode sees an electrical impulse as coming head on, it will write the highest amplitude deflection on the EKG paper.

3
l Principle # 2 : When the positive sensing electrode sees an electrical impulse crossing it on a perpendicular path, it will write the smallest amplitude deflection on the EKG paper.

4
Quadrants l If the electrical axis of the heart is between + 0 & +90 degrees, the axis is said to be in the normal quadrant

5
l If the electrical axis of the heart is between -0 & -90 degrees, it is said to be in left axis deviation

6
l If the electrical axis of the heart is between +90 and +180 degrees, it is said to be in right axis deviation

7
l If the electrical axis of the heart is between -180 and -90 degrees, it is said to be in extreme right axis deviation

9
Now, How Do We Determine Axis ? l Look at Lead I and aVF

10
l Step #1 : Determine if the overall QRS complex deflection is grossly positive or grossly negative in Leads I and aVF

11
l Step #2 : If the QRS are both positively deflected, then the electrical axis is in the normal quadrant (up,up)

12
l If the QRS complex for Lead I is positively deflected but the QRS in avF is negatively deflected, then the electrical axis is said to be left axis deviated (up,down)

13
l If the QRS complex in Lead I is negatively deflected but the QRS in aVF is positively deflected, then the electrical axis is said to be right axis deviated (down,up)

14
l If the QRS in Lead I and in aVF are both negatively deflected, the electrical axis is said to be extreme right axis deviated (down,down)

15
Fine Tuning l It is not enough to merely determine the quadrant. It is better to be able to determine where in the quadrant the axis is located.

16
The Tools To Fine Tune l Determine the quadrant l Find the smallest QRS deflection in the six standard leads

17
l Rotate 90 degrees from the smallest electrode into the quadrant that Lead I & aVF said the axis would be located.

18
l Determine if the QRS complex of the smallest deflection is grossly positive or negative.

19
l If the R wave to S wave difference is 0-1 mm, make no fine adjustments in the axis degree setting.

20
l If the R wave to S wave difference is between 2-3 mm, then adjust the axis 10 degrees towards the + or - pole of the smallest QRS.

21
l If the smallest QRS deflection is grossly negative, the fine adjustment of 10 degrees is swung toward the negative pole of that lead.

22
l If the smallest QRS deflection is grossly positive, the fine adjustment of 10 degrees is swung toward the positive pole of that lead.

23
l If the R wave to S wave difference is between 4-5 mm, then adjust the axis 15 degrees towards the + or - pole of the smallest QRS.

Similar presentations

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google