A guide catheter extension device for use with a standard guide catheter. The guide catheter extension device is made up of a flexible, elongate extension catheter having a tapered tip portion at a distal end, an opening at a proximal end, and a body portion extending between the two. The extension catheter has a longitudinal slit extending from the distal tip portion toward the proximal opening. Methods of using the guide catheter extension device to aid in performing interventional cardiology procedures.
