Electrical axis

Figure 6. Orientation of magnetic field, electric axis, and rotation axes in Al(III)...

The Hamiltonian operator for a hydrogen atom in a unifonn external electric axis i -fd. 

Figure 10.5 Einthoven s triangle. The triangle is in the frontal plane of the patient, m is the heart vector bound to the center of the heart u is the instantaneous scalar voltage measured in a respective lead a is the instantaneous angle of the electric axis of the heart.

The full derivation of this approach can be found in ref. 29. In summary, from Maxwell s equations we first consider the general case of a 4x4 transfer matrix for electromagnetic materials, followed by the specific case of a screwlike electrical axis. 

This chart will help you quickly determine the direction of a patient s electrical axis. Observe the deflections of the QRS complexes in leads I and aVp. Lead I indicates whether impulses are moving to the right or left, and lead aVp indicates whether they re moving up or down. Then check the chart to determine whether the patient s axis is normal or has a left, right, or extreme right deviation. 

The degree method provides a more precise measurement of the electrical axis. It allows you to identify a patient s electrical axis by degrees on the hexaxial system, not just by quadrant. 

Calculating the electrical axis is often considered one of the more complex elements of ECG interpretation. The electrical axis refers to the net or overall direction in which the electrical current travels in during ventricular depolarisation. This is achieved by adding together the sum of all of the individual vectors to determine the overall direction of the flow across the whole myocardium. Calculating the electrical axis is useful as it can provide additional evidence for the presence of various conditions. 

Q4. Which two leads are used to determine the electrical axis ... 

Finding the patient s electrical axis can help confirm a diagnosis. 

A more precise axis calculation, the degree method provides an exact measurement of the electrical axis. It allows you to identify a patient s electrical axis by degrees on the hexaxial system, not just by quadrant. It also allows you to determine the axis even if the QRS complex isn t clearly positive or negative in leads I and aVp. To use this method, take the following steps. 

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