QRS axis: Difference between revisions

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When you average all electrical signals from the heart, you can indicate the direction of the average electrical depolarization with an arrow (vector). This is the heartaxis. Especially a change of the heartaxis or an extreme deviation can be an indication for pathology.
When you average all electrical signals from the heart, you can indicate the direction of the average electrical depolarization with an arrow (vector). This is the heartaxis. Especially a change of the heartaxis or an extreme deviation can be an indication for pathology.
*Largest QRS deflection in lead I: the electrical activity is directed to the left (of the patient)
*Positive (the average of the QRS surface above the baseline) QRS deflection in lead I: the electrical activity is directed to the left (of the patient)
*Largest QRS deflection in lead AVF: the electrical activity is directed down.
*Positive QRS deflection in lead AVF: the electrical activity is directed down.
This indicates a normal heartaxis. Usually, these two leads are enough to diagnose a normal heartaxis!
This indicates a normal heartaxis. Usually, these two leads are enough to diagnose a normal heartaxis!


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