A guide wire configured for intravascular insertion includes a core wire having a flattened portion configured to allow the core wire to preferentially bend in at least one plane that passes through a longitudinal axis of the core wire. A distal most end of the flattened portion is spaced from a distal most end of the core wire. The guide wire may further include a sensor element configured to measure a physiological variable in a living body and a coil surrounding a portion of the core wire.
