how to measure ekg waves
Electrical axis and recording lead vectors (see Figures 2 and 3) The ECG is measured by placing a series of electrodes on the patientâs skin â so it is known as the âsurfaceâ ECG. The wave of electrical depolarisation spreads from the atria down though the IVS to the ventricles. So the direction of this depolarisation is usually from the superior to the inferior aspect of the heart.