ECG Electrical Axis Classification

ECG Electrical Axis Classification

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If the QRS complex is isoelectric in a lead, then the ventricular axis is —— to that lead

[A] 0 degrees
[B] 60 degrees
[C] 90 degrees
[D] 180 degrees

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ECG Electrical Axis Classification

If the QRS complex is isoelectric in a lead, then the ventricular axis is perpendicular (90 degrees) to that lead

Electrical Axis Classification

What are the five main electrical axis classifications?

1. Normal axis
2. Left axis deviation (LAD)
3. Right axis deviation (RAD)
4. Extreme axis deviation, and 
5. Indeterminate axis 

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What is the Normal QRS Axis in ECG?

Normal QRS axis

1. At birth – between +30 degrees and +190 degrees.
2. Ages of 8 to 16 – axis moves leftward with normal lying between 0 degrees to +120 degrees.
3. The normal adult QRS axis is between -30 degrees and +90 degrees, which is directed downward and to the left.
4. This adult range is sometimes extended from -30 degrees to +100 degrees.

Electrical Axis (from TheEKGGuy.com with permission). Contributed by Anthony H. Kashou, www.theekgguy.com. Copyright © 2023, StatPearls Publishing LLC.

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