Intravascular devices, systems, and methods are disclosed. In some embodiments, side-loading electrical connectors for use with intravascular devices are provided. The side-loading electrical connector has at least one electrical contact configured to interface with an electrical connector of the intravascular device. A first connection piece of the side-loading electrical connector is movable relative to a second connection piece such that in an open position an elongated opening is formed between the first and second connection pieces to facilitate side-loading of the intravascular device into the connector and in the closed position the at least one electrical contact is electrically coupled to the at least one electrical connector of the intravascular device received between the first and second connection pieces and a communication cable extends from the connector in a direction coaxial with or parallel to the longitudinal axis of the intravascular device.