Intravascular blood pressure monitoring devices and methods that include an indwelling portion and a pressure transducer. The indwelling portion may include a tubular member, at least a portion of the tubular member configured to transmit fluid pressure from blood that is external to the tubular member to a fluid disposed within the tubular member, and the tubular member may be adapted to isolate the fluid from the blood, with the fluid within the tubular member being in pressure communication with a pressure transducer. The devices may include a stiffening member interface adapted to releasably interface with a stiffening member to stiffen at least a portion of the indwelling portion while delivering the indwelling portion to a position within the subject, and causing the indwelling portion to be less stiff after its removal.
