### Voltage:

This is **V**ictor, he represents **V**oltage (**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 **R**icky, he represents the **impedance** or the sum of all **R**esistance 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 **R**icky opposing the flow of the current with the use of **impedance** (**R**).

**Voltage = V**

**Current = I**

**Impedance (Resistance) = R**