We have developed this Heart Axis Calculator, since we know that as health professionals sometimes we do not have much time. For this reason, this tool is very useful to perform a quick and exact calculation of the Cardiac Axis in the Electrocardiogram.
This Cardiac Axis Calculator works by the mathematical model to calculate the Exact Cardiac Axis. To be able to use it, only the net amplitudes of the QRS Complexes of D1 and D3 must be entered. It is important to place the negative or positive numbers as appropriate.
Contenido a revisar
Exact Cardiac Axis Calculator
Calculadora de Eje Cardíaco

How to use the Heart Axis Calculator?

In order to use the Cardiac Axis Calculator, the values of the net amplitudes of the QRS of Leads D1 and D3 must be entered.
Remember that to obtain the net amplitude of a QRS Complex it is necessary to subtract its amplitudes.
A QRS Complex is made up of positive waves (R wave) and negative waves (Q or S wave). To obtain the net amplitude then it is necessary to subtract the positive waves from the negative ones of greater amplitude.
This process is repeated in both D1 and D3 to obtain the values to be entered in the Cardiac Axis Calculator.
In Figure 1. You can see a QRS Complex. If we calculate the net amplitude of Figure 1. We will obtain a value of 12 mm (16mm – 4mm). Here you can read more about how to calculate the net amplitude of a QRS complex.
¿Porque usamos DI y DIII en lugar de DI y aVF?
It has been found that using a monopolar lead with a bipolar lead to calculate the Electrical Axis of the heart generates important calculation differences.
Using Leads D1 and D3 using the corrected Cardiac Axis Calculation formula offers more accurate results. This model allows a better adaptation of the Cartesian plane to the Hexaxial System. This formula also eliminates the problem of non-equivalent QRS.
When using two bipolar leads to calculate the Exact Cardiac Axis, the amplitudes of the QRS complexes are equivalent. This not only facilitates obtaining data, it also reduces the possibility of errors and therefore gives greater accuracy to the calculation.
Cardiac Axis Calculator APP.
We have developed the Cardiac Axis Calculator Android mobile application. Now you can have this tool and use it anytime, anywhere.
Other methods to calculate the Cardiac Axis
Remember that the Heart Axis Calculator uses the manual method to calculate the Exact Heart Axis. The most accurate method. However, this is not the only method to determine the Cardiac Axis. It is also possible to obtain a fairly precise value using the graphical solution or the Isodiphasic method for calculating the Cardiac Axis.

MD. University teacher. Passionate about internal medicine. Biochemistry and Pathophysiology are my favorite subjects. I have created this website as a portal to help understand certain topics and as a source of review.