Intravascular devices and systems include a flexible elongate member having a component configured to detect a physiological condition of a patient when the flexible elongate member is in a vasculature of the patient. The probe may also include a connector junction non-rotatably and permanently secured to the proximal portion of the flexible elongate member. The connector junction may be sized for grasping by a health care provider and for rotation to rotate the flexible elongate member when the flexible elongate member is in a vasculature of the patient. The connector junction may include a slack chamber to accommodate slack in a conductor that may be utilized when the flexible elongate member is introduced through tortious vasculature.