Positive fixation device

Claim 1

An implantable defibrillation electrode comprising: an electro-catheter including a conductive distal end portion and a non-conductive proximal end portion, at least a major portion of the length of said distal end portion having a pre-configured shape and being resiliently deformable into a generally straight condition, said distal end portion including distal and proximal ends, at least one of said distal and proximal ends being hollow, hook means, shiftably supported in said at least one of said distal and proximal ends, for engaging body tissue and including a reversed turned free end portion and a mounted base end portion, said hook means further including a bend therein intermediate said free end portion and said base end portion contained within said hollow end when said hook means is in a retracted position and projectable outwardly of said hollow end when said hook means is in an extended position for lateral displacement of said hook means relative to said hollow end during final displacement of said hook means to said extended position, means for moving said hook means longitudinally of said electro-catheter from said retracted position, in which said hook means is at least substantially entirely contained within said hollow end, and said extended position, in which said hook means is substantially fully outwardly projected from said hollow end, and means for yieldingly biasing said hook means from said extended position toward said retracted position, and axial thrust developing means being slidingly telescoped through said proximal end portion and operatively associated with said hook means in order to exert an axial thrust thereon from a terminal end of said proximal end portion.