A system for accessing arterial vasculature from a venous insertion site includes a first elongate tubular member, a second elongate tubular member configured to be disposed within a lumen of the first elongate tubular member, an elongate crossing member including a distal tip comprising a frusto-conical outer surface, and configured to be disposed within a first lumen of the second elongate tubular member, and a stylet configured to be disposed within a lumen of the elongate crossing member, wherein placement of the second elongate tubular member, elongate crossing member, and stylet together through the lumen of the first elongate tubular member does not substantially straighten a curved distal portion of the first elongate tubular member, and wherein the elongate crossing member and stylet are removable from the first lumen of the second elongate tubular member when it is within the lumen of the first elongate tubular member with at least its distal end extending out of the first elongate tubular member.
