A normal axis, in the context of electrocardiography (ECG), refers to the direction of the heart's electrical activity during ventricular depolarization (the QRS complex) falling within a specific range.
According to the provided reference: the normal axis is between -30° and +90°. This signifies that the primary direction of the QRS vector is generally directed downward and slightly to the left. Deviation outside this range may indicate heart conditions or abnormalities.
Understanding Axis Deviation
Axis deviation refers to when the heart's electrical axis falls outside the normal range. Here's a brief overview from the reference:
- Left Axis Deviation (LAD): Between -30° and -90°. The QRS vector points upward and to the left.
While the reference primarily defines the normal axis and LAD, understanding these deviations helps provide context to what constitutes a "normal" axis.
Summary
In summary, a normal axis on an ECG indicates that the heart's electrical activity is within the expected range of -30° to +90°, suggesting typical electrical conduction through the ventricles.
