Abstract: A lead assembly for fixation to a human heart via thoracoscopy is provided. The lead assembly includes a lead that has a connector for connection to a cardiac stimulator, such as a pacemaker, a cardioverter/defibrillator, or a sensing instrument. A fixation mechanism is coupled to the lead that includes a tubular housing and a proximally projecting hook that is adapted to engage heart tissue. The hook is pivotable between a retracted position and an extended position. The lead and the hook are manipulated by a stylet. The lead assembly also includes a tubular introducer that is passed through the chest wall of a patient and used to place the lead proximate the epicardium.

Abstract: A catheter system having a tip with fixation tines for use in treatment of tissues, such as ablating tumors in a natural body conduit or a cavity by applying RF energy through the tip, wherein the catheter system passes through a natural body opening to reach the target tissues, wherein the catheter system stays at a desired position via its fixation tines and delivers therapeutic RF energy to the target tissues for improved tissue treatment.

Abstract: A continuous sheath of open-celled porous plastic, preferably ePTFE, is used on the outside of an implantable lead, extending along the lead body and the electrodes, in such a way that the lead is isodiametric along its length, and is very strong in tension as is required for lead removal. Because the plastic is open-celled, when the pores are filled with saline, the lead can deliver defibrillation energy through the pores in the plastic. Pore size is chosen to discourage tissue ingrowth while allowing for defibrillation energy delivery through it.

Abstract: A recording/ablation system includes an inner working catheter for deployment from a distal port in an outer sheath or catheter in a heart chamber, or the like, which has a plurality of divergent electroded spines each constrained at the proximal end with a substantially free distal end for controlled separation. The divergent electroded spines are collapsible to a substantially parallel configuration for transport and stowage. A single deflecting spine version is also disclosed.

Abstract: An electrode device, for intracardiac stimulation of heart tissue and/or sensing heart signals in a patient, has an electrode cable containing at least two elongate, flexible conductors, insulated from each other, and with an electrode head, arranged at the distal end of the electrode cable and at least two conductive surfaces, each connected to a separate conductor. In order to permit the distance between the conductive surfaces to be varied over a continuous range, simply and easily, the electrode head has at least two parts, moveable in relation to each other, each part being provided with at least one conductive surface, and the a control element is movably arranged at the distal end of the electrode cable immediately behind the electrode head, so any change in the position of the control element causes the control element to act on the parts of the electrode head such that the distance between the conductive surfaces is varied.

Abstract: An implantable endocardial lead with a retractable helix. A specialized stylet can be inserted into the lead at the proximal end and passed through the lead to the distal end. Located at the distal end of the lead is a piston supporting the helix. The piston is attached to a coiled trifilar conductor and has an electrode adjacent the helix. Immediately adjacent the piston proximally an additional first short coil of wire is interlocked between the wires of the trifilar conductor, providing a female thread within the conductor. The stylet has a second single strand short coil segment spot welded to the stylet adjacent a distal end thereof. The stylet is rotated to screw the second short coil segment on the stylet into the first short coil adjacent the piston.

Abstract: A lead having a defibrillation electrode that is deployed for defibrillation using artificial muscle. In an undeployed position, the defibrillation electrode is small in diameter so as to be easily implanted pervenously and nonobstructive to cardiac contraction and blood flow. In a deployed position the defibrillation electrode is larger in diameter for defibrillation shock delivery. Thus, the electrode forces an increased amount of current to flow through the heart muscle during shock delivery to depolarize the majority of the cardiac tissue with a minimum of energy, while not obstructing blood flow at other times when not used for energy delivery.

Abstract: A transvenous implantable defibrillation lead includes a conductor and inner and outer coaxial cylindrical electrodes. The inner electrode is connected to the conductor, and the outer electrode is connected to a sheath overlying the conductor in rotatable relationship thereto. The sheath is fixed to the outer cylindrical electrode so that rotation of the sheath relative to the conductor results in rotation of the inner and outer cylindrical electrodes relative to each other. The inner electrode has a plurality of hooks extending generally transversely and tangentially thereto, with the hooks being biased such that the terminal ends of the hooks tend to spring outwardly from the inner electrode. The hooks are constrained against the inner cylindrical electrode by the outer cylindrical electrode, except that a window in the outer electrode permits the hooks to spring outwardly therethrough upon rotation of the outer electrode relative to the inner electrode.

Abstract: An implantable devices for the effective elimination of an arrhythmogenic site from the myocardium is presented. By inserting small biocompatible conductors and/or insulators into the heart tissue at the arrhythmogenic site, it is possible to effectively eliminate a portion of the tissue from the electric field and current paths within the heart. The device would act as an alternative to the standard techniques for the removal of tissue from the effective contribution to the hearts electrical action which require the destruction of tissue via energy transfer (RF, microwave, cryogenic, etc.). This device is a significant improvement in the state of the art in that it does not require tissue necrosis.In one preferred embodiment the device is a non conductive helix that is permanently implanted into the heart wall around the arrhythmogenic site.

Abstract: A joint for cardiac stimulation lead has a sleeve that joins a conductor to an electrode. The conductor and electrode are inserted into passages formed through the sleeve and are bonded at least to the sleeve surface by laser welding, crimping, or resistance welding. The distal end of the conductor is attached to the sleeve and either the proximal end or the distal end of the electrode may be attached to the sleeve. The number, size, shape and positioning of passages in the sleeve are varied according to the desired lead configuration to allow passage of additional conductors through the joint.

Abstract: A lead for use with a pacemaker in a pacing system, the lead having at least one electrode placed at its distal tip and a helical fixation member at the lead distal tip for screwing the lead into a patient's heart wall. The helical member is composed of shape-memory metal and until use is encapsulated in a shrunken state with a diameter less than the diameter of the lead casing. The encapsulation material is preferably mannitol or a like material which dissolves when placed in the human heart. The shape-memory helix when released from the encapsulation material assumes an expanded diameter, greater than electrode diameter and preferably greater, so that when it is screwed into the heart wall, the helical coils are displaced radially away from the outer edge of the tip electrode. By this design, the damage to the heart tissue caused by the helix does not affect the heart wall immediately proximate to the tip electrode.

Abstract: An implantable defibrillation electrode including a conductive distal end portion and a non-conductive proximal end portion is provided with at least a major portion of the length of the distal end portion having a pre-configured shape and being resiliently deformable into a generally straight condition. The distal end portion includes distal and proximal ends and at least one of those ends is hollow and has hook structure shiftably supported therein for movement longitudinally thereof from a retracted position at least substantially contained within the hollow end and an extended position at least substantially fully outwardly projected from the hollow end.

Abstract: The mapping and/or ablation catheter for use in ablating the tissue in the wall forming a chamber in the heart comprising a flexible elongate tubular member having proximal and distal extremities, end cap formed of a conductive material mounted on the distal extremity of the flexible elongate tubular member, a fixation means carried by the end cap for engaging the wall of the heart and for retaining the end cap in a predetermined position on the wall of the heart during beating of the heart, said fixation means being movable between tissue engaging and disengaging positions. The means carried by the proximal extremity of the flexible elongate tubular member for moving the fixation means between the engaging and disengaging positions.

Abstract: Electrophysiology catheter apparatus including at least one retractable control wire with a preformed curved resilient foot formed at the distal extremity, slidably advanced and retracted within a longitudinal lumen of a catheter tube for controllably anchoring to a selected endocardial heart tissue. The proximal end of the control wire is formed with a handle to be grasped to slidably advance the preformed resilient foot beyond the distal tip of a catheter to project laterally to contact the adjacent tissue.

Abstract: A heart signal sensor 11 is connected by a flexible cord 13 to a catheter 17. The sensor 11 and the catheter 17 are attached to install the sensor in the cardiac wall, and thereafter are disunited and separately attached to the cardiac wall 1. The sensor is attached to the cardiac wall by claws projecting from the sensor surface, and may be installed by rotating or by deformation of the sensor.

Abstract: A medical electrical lead of the type which includes an electrode at a distal end of the lead a connector at a proximal end of the lead and an elongated electrical conductor extending between the electrode and the connector. The conductor is comprised of a wire wound in a coil configuration with the wire comprised of a super austenitic stainless steel having a composition of at least 22% nickel and 2% molybdenum. Material of such composition has been found to have suitable conductivity for use with implantable pulse generators and suitable fatigue strength when used in endocardial lead placement. Moreover, such material has been found to pass tests intended to detect metal ion oxidation (MIO) in polymeric materials.

Abstract: An implantable defibrillation electrode including a conductive distal end portion and a non-conductive proximal end portion is provided with at least a major portion of the length of the distal end portion having a pre-configured shape and being resiliently deformable into a generally straight condition. The distal end portion includes distal and proximal ends and at least one of those ends is hollow and has hook structure shiftably supported therein for movement longitudinally thereof from a retracted position at least substantially contained within the hollow end and an extended position at least substantially fully outwardly projected from the hollow end.

Abstract: A defibrillation lead for location in a human heart, having an elongated lead body defining a generally straight segment extending from its proximal end and a curved segment extending distally from the straight segment. The curved segment has a sigmoidal configuration including a two or more alternating, generally coplanar curves, and carries an elongated defibrillation electrode extending along its length. A stylet is provided for straightening the curved segment prior to implant.

Abstract: A combined pacing and cardioversion lead system with internal electrical switching components for unipolar or bipolar sensing of electrograms, pacing at normal pacing voltages and cardioversion or defibrillation. In bipolar embodiments, an indifferent electrode, closely spaced to a sensing and pacing electrode, is coupled in common through the integral switching circuitry to a large surface area cardioversion electrode. In these embodiments, pacing and sensing is accomplished through a pair of conductors extending through the lead system to the closely spaced active and indifferent electrode pair. When cardioversion energy is applied to the indifferent electrode, the cardioversion energy is also directed to the cardioversion electrode through operation of the switching circuitry in response to the magnitude of the applied cardioversion pulse. In unipolar embodiments, a distal sensing and pacing electrode is coupled through integral switching circuitry to a large surface area cardioversion electrode.

Abstract: An implantable defibrillation electrode including a conductive distal end portion and a non-conductive proximal end portion is provided with at least a major portion of the length of the distal end portion having a preconfigured shape and being resiliently deformable into a generally straight condition. The distal end portion includes distal and proximal ends and at least one of those ends is hollow and has hook structure shiftably supported therein for movement longitudinally thereof from a retracted position at least substantially contained within the hollow end and an extended position at least substantially fully outwardly projected from the hollow end.

Abstract: An implantable defibrillator lead comprises a flexible, conductive lead member having proximal and distal end portions. The distal end portion defines a plurality of separate, curvilinear electrodes which naturally extend laterally outwardly in a curved arrangement from the remainder of the lead. However, by desired means, the curvilinear electrodes may be temporarily extended out straight, substantially parallel to the axis of the remainder of said lead member, to facilitate implantation of the lead. This may be preferably accomplished by a flexible sheath that encloses the lead member in longitudinally slidable relation.

Abstract: A low impedence defibrillation catheter electrode having a high effective conductive length for implantation in the right ventricle of the heart. The catheter electrode conductive body has at least one flexible and resilient extension member extending angularly therefrom. The flexible and resilient conductive members provide an increased effective length to the catheter electrode and permit collapse into a small diameter configuration for insertion into an introducer structure for implantation through a venous approach.