Voltage:
This is Victor, he represents Voltage (V) today. The terms “amplitude” and “voltage” are often used interchangeably. Voltage is the force or push that causes electrons to move through a circuit.
Current:
These blue circles represent flow of electrons or current measured in mA, milliamps. The symbol for current is I.
Impedance:
This is Ricky, he represents the impedance or the sum of all Resistance to the flow of current. It is the opposition to flow.
The resistive factors to a pacing system include, lead conductor resistance, the resistance to current flow from the electrode to the myocardium and polarization impedance.
Resistance is a term used to refer to simple electric circuits without capacitors and with constant voltage and current like a light bulb circuit. Impedance is a term used to describe more complex circuits with capacitors and with varying voltage and current. Therefore, the use of the term impedance is more appropriate than resistance when discussing pacing circuits and electrophysiology.
So, putting this all together in this image, Victor is the voltage (V) push on the electron current (I) with Ricky opposing the flow of the current with the use of impedance (R).
Voltage = V
Current = I
Impedance (Resistance) = R
