By use of three sensors, one each placed on the right arm, left arm and left leg, we are able to obtain six different views.
The first three views I will review are called Standard Leads I, II and III
These views are referred to as "bipolar leads" due to two sensors utilized on the skin surface (one is positive and the other is negative – just like a battery) to complete the circuit.
The other three views are aVR, aVL and aVF. These will be discussed shortly.
One last comment, direct views of the heart will always be from the position of the positive pole i.e. Lead II and aVF positive pole is the left leg. These would be "inferior" views.