Abstract: The components of an adaptor device for use with cardiac pacemaker electrode catheters include a conductive element, typically a stilet, serving to ensure a sound connection between the already implanted spiral wound wire and a new pacemaker: in the improved adaptor, the conductive element is flexible, appearing as a further spiral wound wire secured by one end to a spindle and extending from the tip of the spindle along the entire length of the implanted wire in such a way as to terminate near the stimulation electrode, which is anchored in a ventricular wall of the cardiac muscle.

Abstract: An electrode catheter for intravenous insertion into a cavity of the heart comprises a tubular sheath accommodating a first spiral wound wire of conductive biocompatible material, which affords an insulated operative portion exposed from the sheath and capped distally by a domed ring, and a mapping electrode of conductive biocompatible material for sensing the electrical activity in the cardiac muscle, which is carried coaxially by the first spiral wound wire and capable of movement along the operative portion transmitted by means of a second spiral wound wire extending coaxially through the first and connected to an external control handset. The operative portion of the first wire is arched by means of a tension wire designed to establish a restraint between the domed ring and the distal end of the sheath, of which the length can be increased or reduced to alter the loop of the arched profile as expedient for the shape of the cavity explored.

Abstract: A replacement cardiac pacemaker is connected to an already implanted electrode catheter from which the original connecting pin has been discarded, and the cut end of the severed spiral wound wire bared from its sheath, by an adaptor that comprises a sleeve accommodating a conductive spindle rotatable about its own axis and rigidly associated with a coaxial stilet projecting from an open socket end of the sleeve and insertable tightly into the bore of the bared wire; the sleeve also accommodates a second spiral wound wire interposed between the sleeve and the corresponding section of the stilet, attached by its ends respectively to the socket end and to the spindle, and a detachable key by means of which the spindle can be rotated in such a way as to subject the second wire to a torsional stress that results in the first wire being restrained against the stilet. The interlocked wires and stilet are encapsulated in an insulating outer sheath and made secure with surgical threads bound firmly around the sheath.

Abstract: The electrode comprises an anchor point sandwiched firmly between a protective insulating sheath and an enlarged end portion of the selfsame sheath in such a way that the tip of the point projects from the distal end, together with a stimulation head disposed coaxially with the sheath and connected electrically to a spiral wound conductor; when the anchor point is corkscrewed into a cardiac muscle, a conductive spring positioned between the head and the conductor allows a measured retraction of the head back into the sheath, with the result that the head is maintained constantly in contact with the surface of the cardiac muscle independently of the penetrating movement of the point.