Electro-catheter used in physiological cardiac stimulation simulative of the auriculo-ventricular sequence, featuring active engagement of the cardiac muscle

DETAILED DESCRIPTION The object thus stated is realized with a one-piece catheter as disclosed herein, the two independent electrodes of which are insulated, and arranged such that the one (proximal) is located in the atrium, and the other (distal) is located in the ventricle, the catheter itself being cylindrical in shape and having a distal extremity that incorporates the ventricular electrode, an actively engaging type with a spiral metal anchor (normally platinum-iridium alloy) which may be fixed or retractable.
The spiral, normally of 1 to 3 turns, serves to anchor the electrode; rotating the electrode, or the relative stylet, the anchor corkscrews into the cardiac muscle, drawing it into electrical contact with the cylindrical tip of the electrode.
A conductive cylindrical body, located along the cylindrical body of the catheter at a relative distance of between 10 and 18 cm (4-7 ins), performs the function of atrial electrode.
A spiral hook with a sharp end issuing from this cylindrical body can be rotated through approximately 270.
degree.
by means of a relative stylet.
In a stowed position, the spiral hook wraps around the cylindrical conductor which extends into the ventricle, and lies with its axis of rotation parallel thereto.
The catheter can thus be introduced without the spiral hook penetrating the wall of the cardiac vein, and positioned in such a way that sensitivity and stimulus thresholds are acceptable for operation of the pacemaker, following which the spiral hook is rotated in such a way as to open out toward the wall of the heart, then rotated in the opposite direction so that its sharp point engages and sinks into the cardiac muscle, drawing the cylindrical body of the electrode into close contact therewith.
The electrical contact and mechanical fixture obtained in this way are produced by the simplest of maneuvers, and afford maximum dependability.
Advantages of the invention are essentially (1) that one electro-catheter only is introduced, permitting use of one vena cava only; (2) that the ventricular and auricular electrodes are both made fast mechanically to the ventricle and atrium walls, ensuring efficient electrical contact at the same time, thereby reducing the percentage of removals and subsequent repositioning operations by at least 80%; (3) that the catheter can be implanted utilizing the same surgery technique as is normally adopted for ordinary discrete catheter electrodes