A kit for coronary treatment comprising a pressure sensing guidewire that includes a pressure sensor for measuring pressure within a patient's vasculature. A sheath comprising a tube having a proximal end and a distal end and defining an internal lumen sized for receiving the pressure sensing guidewire; a hemostasis valve positioned over the proximal end of the tube; a cylindrical element attached to the distal end of the tube, the cylindrical element having an internal lumen sized for receiving a conventional guidewire; wherein the pressure sensing guidewire is configured to be slideably insertable into the tube from the proximal end of the tube; and further wherein, the tube is configured to permit the pressure sensing guidewire, including the pressure sensor, to freely slide distally and proximally within the tube at the election of a user.