A magnetically navigable 
catheter includes a sheath having a proximal end and a distal end, and an extension member having a proximal end and a distal end, slidably mounted in the sheath so that the distal end portion of the extension member telescopes from the distal end of the sheath. The distal end portion of the extension member being relatively more flexible than the distal end of the sheath. There may be one or more electrodes on the distal end of the extension member. There is also at least one 
magnet, and preferably more than one 
magnet, on the distal end portion of the extension member to allow the distal end of extension member to be oriented by the application of an externally applied 
magnetic field. The 
catheter preferably also includes a sleeve, having a proximal end and a distal end, the sleeve being slidably mounted in the sheath so that the distal end portion of the sleeve telescopes from the distal end of the sheath, so that the sleeve can be selectively extended and retracted relative to the sheath, and the extension member can be selectively extended and retracted relative to the sleeve. According to the method of this invention, the distal end of the 
electrode catheter is introduced into the part of the body where the 
electrode will be used to contact the specific body structures, and the 
electrode is moved into contact with the body structure by applying an external 
magnetic field and selectively telescoping the extension member relative to the sheath to bring the electrode on the distal end of the extension member into contact with the specific body structure.