A positively anchored retractable tripolar catheter for endocardial pacemaker electrodes

Claim 1

A positively anchorable retractable tripolar catheter for endocardial pacemaker electrodes, which comprises a flexible tubular casing (1) of biocompatible material fitted with a ventricular electrode (2) at the leading end and ensheathing: - a first conductor (3) of spiral-wound electrically conductive wire accommodated within a first tubular sheath (4) fashioned in a flexible and electrically insulating material, internally of which the spiral wound wire is rotatable and longitudinally slidable within and in relation to the casing (1), of which one end is connectable by way of a first contact (5) to a first terminal of a cardiac pacemaker and the remaining end is fastened to an electrically conductive helicoid point (6) capable of movement, produced by rotation of the first conductor (3), from a position retracted internally of the casing to a position projecting from the casing, in such a way as to anchor in a ventricular cardiac muscle; - a second spiral-wound conductor (7) accommodated within a second tubular sheath (8) similar to the first sheath (4) and disposed parallel with the first conductor (3) internally of the casing (1), of which one end is connectable by way of a second contact (9) to a second terminal of the pacemaker and the remaining end is connected to a first atrial electrode consisting of a first ring (10) of biocompatible metal positioned externally of the casing (1) at a predetermined distance from the point (6); - a third spiral-wound conductor (11) disposed parallel with the first and the second conductors internally of the casing (1), of which one end is connectable by way of a third contact (12) to a third terminal of the pacemaker and the remaining end is connected to a second atrial electrode consisting of a second biocompatible metal ring (13) positioned externally of the casing (1) at a given distance from the first ring (10); and in that the first contact (5) is separated from the casing (1) in order to permit connection of the electrodes and the pacemaker by way of two distinct and substantially parallel leads (L, L1), the one unipolar and the other bipolar.