Abstract: The present invention relates generally to medical devices; in particular and without limitation, to unique electrodes and/or electrical lead assemblies for stimulating cardiac tissue, muscle tissue, neurological tissue, brain tissue and/or organ tissue; to electrophysiology mapping and ablation catheters for monitoring and selectively altering physiologic conduction pathways; and, wherein said electrodes, lead assemblies and catheters optionally include fluid irrigation conduit(s) for providing therapeutic and/or performance enhancing materials to adjacent biological tissue, and wherein each said device is coupled to or incorporates nanostructure or materials therein. The present invention also provides methods for fabricating, deploying, and operating such medical devices.

Abstract: A medical electrical lead and body implantable electrode suitable for a variety of medical applications are disclosed. In general, the electrode includes a composite material having particles of pseudo-capacitive material, such as iridium oxide, dispersed within a polymer matrix including a polyelectrolyte. The polymer matrix can also include a conductive polymer doped with an excess of the polyelectrolyte. The composite may used to form the electrode itself or an electrode coating. The presence of a pseudo-capacitive material within the composite may increase the charge-storage capacity of the electrode and may allow for safe deliveries of charge densities within an electrochemical window suitable for pacing a patient's heart.

Abstract: An implantable tissue-stimulating device for an implantee. The device comprising an elongate member having at least one electrode. At least a portion of the device is coated with a coating that at least partially inhibits adhesion of organic molecules to the device following implantation.

Abstract: A medical device having at least one glass coating between a first and second component. The glass coating forms a portion of a strong, hydrothermally stable joint between components or provides insulation, or tailors an impedance and/or capacitance of an electrode.

Abstract: An electrode device for physiological use, in particular in cardiology, that has an electrically insulating, elastic electrode body which, between internal and external layers (1, 2), has an intermediate layer (3) tailored to their physical properties.

Abstract: Electrodes include a coating that provides a barrier to fluids and ions within a biological environment. The coating increases the overpotential of the electrode. The coating permits the introduction and use of the electrodes into biological environments without the detrimental complications of electro-chemical reactions typically present with the use of metal and metal-alloy electrodes in such environments.

Abstract: A seal adapted for use with medical devices is provided with a lead having a distal tip electrode. The distal tip of the lead is adapted for implantation on or about the heart and for connection to a system for monitoring or stimulating cardiac activity. The lead can include a fixation helix for securing the electrode to cardiac tissue. The lead assembly can alternatively include an open lumen lead tip. A seal is provided within the lead tip assembly such that the seal is expanded to prevent or limit further entry of fluids through the lead tip. The seal includes an expandable matrix, such as a hydrogel. The seal is formed on or within the lead when the lead and the seal comes into contact with a fluid and expands. The seal is also formed as a plug which is deployed through the medical device, and expands as the plug absorbs fluid. A housing incorporating the seal can also be attached to a portion of the medical device to provide the seal.

Abstract: A lead assembly includes a flexible lead body which extends from a proximal end to a distal end, the lead body includes one or more conductors. The lead assembly further includes an electrode assembly, and at least one coating of insulative material coated directly on at least one conductor.

Abstract: This document discusses, among other things, a lead assembly including a lead body, at least one conductor extending through the lead body, and a covering having varied material properties. In an example, the covering is made by forming pieces of material having varied material properties. In another example, the covering is made by varying parameters such as heat or tension during wrapping of a piece of material onto a lead assembly.

Abstract: An electrode with an electrode surface having a polyoxometalate (POM). The use of POM with an electrode surface increases the active electrochemical surface area, with a resulting increase in capacitance and impedance, and a decrease of polarization losses at the electrode/tissue interface. In addition, electrodes having POM can include pseudo-capacitive properties from their redox properties and charge storage properties.

Abstract: A cardiac rhythm management system provides an endocardial cardiac rhythm management lead with an at least partially dissolvable coating at least partially on insulating portions of the lead body at or near its distal end. Upon dissolution, the coating promotes tissue ingrowth to secure the lead in place within fragile vascular structures or elsewhere. Dissolution of one such coating releases a therapeutic agent, such as a steroid that modifies the fibrotic scar tissue content of tissue ingrowth, such that the resulting bond between the tissue and the lead is weak, so that the lead can be easily extracted if desired. One such lead includes an insulating elongate body carrying at least. The lead also includes an at least partially dissolvable coating on an insulating portion of the peripheral distal lead surface. The coating provides one or more of a rough surface, a porous surface, or a swollen surface after being exposed to an aqueous substance.

Abstract: Implantable cardiac monitoring and stimulation devices and methods using cardiac leads employ coated fixation arrangements. The coating, such as an expanded polytetrafluoroethylene, reduces exit block by reducing the tissue response to the fixation arrangement, decreasing the amount of fibrotic tissue, and reducing exit block. An epicardial lead may include a lead body with one or more electrical conductors with associated insulators and an electrode assembly situated at the distal end. The electrode assembly includes an electrode having an active fixation arrangement such as a helical fixation element. The fixation arrangement is completely or partially coated with a fluoropolymer or has a sleeve on some or all of the active fixation arrangement. The coating or sleeve may include a steroid or other pharmacological eluting arrangement disposed on the active fixation arrangement.

Abstract: A surface area of an IMD electrode is increased by forming a conductive layer over an external portion of a sidewall of an IMD connector header and electrically coupling the conductive layer of the connector header to a conductive mounting surface of a hermetically sealed IMD housing; wherein the conductive mounting surface is an extension of an external conductive surface of the IMD, which external conductive surface forms the IMD electrode that is increased in surface area by the conductive layer formed over the connector header.

Abstract: A low-polarization electrode for use with an implantable lead. The low polarization electrode comprises a base substrate of a conductive material, an intermediate layer of a high dielectric layer over the base substrate, and a polarization-reducing coating over the intermediate layer. The low-polarization electrode essentially operates as a parallel-plate capacitor, thereby alleviating the polarization artifact at an electrode/tissue interface.

Abstract: An implantable device that contains a power source, a device for producing electrical signals, and a conductor assembly for communicating the electrical signals to biological matter. The conductor assembly contains of a conductor that is capable of being flexed at least about 15 degrees and that has a resistivity at 20 degrees Centigrade of from about 1 to about 100 micro ohm-centimeters. The conductor assembly also contains a magnetic shield located above the flexible conductor; the magnetic shield contains an antithrombogenic composition. The magnetic shield also contains a magnetic shielding material that has a magnetic shielding factor of at least about 0.5.

Abstract: An implantable electrode and electrode system for contacting living biological material that includes an electrode assembly including at least a portion of the electrode, adapted to contact the living biological material at an electrode/tissue interface, exhibiting conduction that is substantially limited to electron or electron vacancy conduction. The implantable electrode is manufactured by coupling an electrode to a distal end of a conductor, and forming at least one surface of the electrode with a material that conducts electricity in a manner that is substantially limited to electron or electron vacancy conduction when the at least one surface is in contact with the living matter.

Abstract: A stimulation electrode has an electrode surface at least partially covered with a coating of titanium nitride, the titanium nitride having on its side remote from the electrode surface a larger surface than the region of the electrode surface covered by the titanium nitride. The titanium nitride is covered with at least one oxidation protection layer on its surface remote from the electrode surface. The stimulation electrode is useful, for example, in cardiac pacemakers, neuro-stimulation devices and other human implants.

Abstract: An ionically conductive polymeric composition is disclosed. The composition is especially useful for coating an implantable hot can defibrillator electrode. The polymeric composition, for example, polyethylene oxide containing NaCl or a similar ionic medium, can be used to coat and fill the pores of a high surface area electrode to provide a continuous ionic network from the can to the adjacent body tissue. The conductive polymeric composition is biocompatible, chemically and mechanically stable and does not dissolve or leach out over the useful lifetime of the defibrillator. A hot can defibrillator employing the polymeric coating avoids development of high polarization at the can/tissue interface and maintains a more uniform defibrillation threshold than conventional implantable defibrillators, thus increasing the feasibility of pectoral implantation, particularly in a “dry pocket” environment.

Abstract: An electrode having a substrate with a first layer covering at least a portion of the substrate, and a second layer covering at least a portion of the first layer is disclosed. The first layer includes a porous layer consisting of a carbide, nitride or carbonitride of at least one of the metals titanium, vanadium, zirconium, niobium, molybdenum, hafnium, tantalum or tungsten. The second layer includes iridium. In a method according to the present invention, a substrate is provided. A first layer is provided over at least a portion of the substrate, and a second layer is provided over at least a portion of the first layer. The first layer includes a layer consisting of a carbide, nitride or carbonitride of at least one of the metals titanium, vanadium, zirconium, niobium, molybdenum, hafnium, tantalum or tungsten. The second layer includes iridium.

Abstract: A layered electrode having a large tissue contact area of the portion of the electrode that is electrically active and providing low polarization losses, high pacing impedance and low chronic stimulation voltage. In a fundamental embodiment, the electrode tip has an outer layer of microporous material which is permeable to conductive body fluids which covers a layer of insulating material which is provided with at least one perforation through the thickness of the material. The at least one perforation provides a localized, high current density path. Both of these layers in turn cover the exterior surface of an electrically conductive, preferably metal, electrode body.

Abstract: An implantable stimulating electrode for directly contacting the endocardium of a human heart exhibits low polarization values of less than about 0.3 mV and is intended for use with an implantable lead having an electrical connector coupled to the proximal end of a conductor for releasable attachment to a stimulating pulse generator. The electrode is comprised of a metallic substrate having an initially exposed outer surface substantially covered with a first inner layer of titanium nitride and a second outer layer of platinum black. The first inner layer of titanium nitride has a thickness of less than about 15 microns and the second outer layer of platinum black overlying the layer of titanium nitride, similarly, has a thickness of less than about 15 microns. The invention includes a method of making the implantable stimulating electrode.

Abstract: An implantable stimulating electrode for directly contacting the endocardium of a human heart exhibits low polarization values of less than about 0.3 mV and is intended for use with an implantable lead having an electrical connector coupled to the proximal end of a conductor for releasable attachment to a stimulating pulse generator. The electrode is comprised of a metallic substrate having an initially exposed outer surface substantially covered with a first inner layer of titanium nitride and a second outer layer of platinum black. The first inner layer of titanium nitride has a thickness of less than about 15 microns and the second outer layer of platinum black overlying the layer of titanium nitride, similarly, has a thickness of less than about 15 microns. The invention includes a method of making the implantable stimulating electrode.

Abstract: Device and method are disclosed in which leads with pacing and defibrillating electrodes are implanted into both the right and left ventricles of a patient's heart to enable simultaneous pacing of both ventricles to reduce the width of the QRS complex of the patient's cardiac activity to a more normal duration, and, when appropriate, to apply electrical shock waveforms to both ventricles simultaneously for lower energy defibrillation of the ventricles. In applying the defibrillation therapy, the defibrillating electrode in the left ventricle may be used as the anode and the defibrillating electrode in the right ventricle may be used as the cathode, or both ventricular defibrillating electrodes may be the anode and the metal case in which the shock waveform generator is implanted may be the cathode.

Abstract: An ionically conductive polymeric composition for coating a hot can defibrillator electrode is disclosed. A polymeric coating, such as polyethylene oxide containing NaCl or a similar ionic medium, coats and fills the pores of a high surface area electrode to provide a continuous ionic network from the can to the adjacent body tissue. In certain embodiments, the underlying high surface area, porous electrode is made by chemically etching a smooth electrode surface, such as that of a conventional titanium housing, followed by applying a thin coating of a noble metal such as platinum. In other embodiments, a noble metal or an oxide thereof, such as platinum black or iridium oxide, is applied to a titanium housing to form a porous, high surface area electrode. The conductive polymeric coating is then applied over the porous noble metal or metal oxide.

Abstract: An ionically conductive polymeric composition for coating a hot can defibrillator electrode is disclosed. A polymeric coating, such as polyethylene oxide containing NaCl or a similar ionic medium, coats and fills the pores of a high surface area electrode to provide a continuous ionic network from the can to the adjacent body tissue. In certain embodiments, the underlying high surface area, porous electrode is made by chemically etching a smooth electrode surface, such as that of a conventional titanium housing, followed by applying a thin coating of a noble metal such as platinum. In other embodiments, a noble metal or an oxide thereof, such as platinum black or iridium oxide, is applied to a titanium housing to form a porous, high surface area electrode. The conductive polymeric coating is then applied over the porous noble metal or metal oxide.

Abstract: An electrode having a substrate with a first layer covering at least a portion of the substrate, and a second layer covering at least a portion of the first layer is disclosed. The first layer includes a porous layer consisting of a carbide, nitride or carbonitride of at least one of the metals titanium, vanadium, zirconium, niobium, molybdenum, hafnium, tantalum or tungsten. The second layer includes iridium.

Abstract: An ionically conductive polymeric composition for coating a hot can defibrillator electrode. A polymeric coating, such as polyethylene oxide containing NaCl or a similar ionic medium, coats and fills the pores of a high surface area electrode to provide a continuous ionic network from the can to the adjacent body tissue. In certain embodiments, the underlying high surface area, porous electrode is made by chemically etching a smooth electrode surface, such as that of a conventional titanium housing, followed by applying a thin coating of a noble metal such as platinum. In other embodiments, a noble metal or an oxide thereof, such as platinum black or iridium oxide, is applied to a titanium housing to form a porous, high surface area electrode. The conductive polymeric coating is then applied over the porous noble metal or metal oxide.

Abstract: A removable lead for applying electrical signals to excitable tissue in a body of a subject, including at least one conductive wire and at least one electrode fixed to the wire. The electrode includes a conducting substrate having a given capacitance and a given resistance and a coating applied over the conducting substrate, such that the capacitance of the electrode with the coating is at least twice the capacitance of the substrate, and the resistance of the electrode with the coating is generally equal to the resistance of the substrate.

Abstract: Medical electrical leads for sensing or electrical stimulation of body organs or tissues, particularly implantable cardiac leads for delivering pacing pulses and cardioversion/defibrillation shocks, and/or sensing the cardiac electrogram (EGM) or other physiologic data and their methods of fabrication are disclosed. A lead body sheath is co-extruded in a co-extrusion process using biocompatible, electrically insulating, materials of differing durometers in differing axial sections thereof, resulting in a unitary lead body sheath having differing stiffness sections including axial segments or webs or lumen encircling rings or other structures in its cross-section. The lead body sheath is co-extruded to have an outer surface adapted to be exposed to the environment or to be enclosed within an outer sheath and to have a plurality of lead conductor lumens for receiving and enclosing a like plurality of lead conductors of the same or differing types.

Abstract: An electrode for a cardiac lead and method of making the same are provided. The electrode includes an electrode member and a coating applied to the electrode member. The coating is composed of an electrically insulating material and covers a first portion of the exterior of the electrode member while leaving a preselected second portion thereof exposed. The second or exposed portion enhances the impedance of the electrode, resulting in power savings and extended life spans for implantable stimulation and sensing devices. Exemplary materials for the coating includes diamond-like carbon and sapphire.

Abstract: A lead with an increased impedance for an active implantable medical device, in particular for a pacemaker. The lead comprises a cylindrical body (14) presenting at its distal end a contact surface (30) for making contact with the endocardium, which is electrically insulated, and a stimulation electrode (16), which is electrically conducting and which is connected to a conductor of the lead. The electrode (16) has at least one active element (22), for example, a plurality of protuberances (22), each one presenting at least an exposed extremity tip (26) having a hemispherical area, making a ledge compared to the contact surface (i.e., protruding) therefrom. The active element presents on at least a part of its exposed extremity to be placed in contact with the endocardium a radius of curvature less than 0.5 mm, more preferably less than or equal to 0.3 mm.

Abstract: An implantable stimulation electrode for use with an implantable tissue stimulator, in particular a pacemaker, defibrillator, bone or neurostimulator, having a metal substrate body and a coating, applied to the substrate body, for reducing the electrode impedance and/or increasing the tissue compatability, in which a ultrathin, specifically functionalized organic coating forming the entire outer surface of the stimulation electrode is provided, which adheres to the underlying surface as a consequence of irreversible physisorption or covalent chemical bonding.

Abstract: An extractable lead and method for chronic blood contacting use. The new lead contains a hydrogel coating having a thickness increase greater than 10% when hydrated. A thick coating is used to provide a shear layer so that the coating tears during extraction, either at the coating/lead interface, between layers of the coating itself, or at the coating/tissue interface. Furthermore, because of the flexibility of such a thick coating, contracture of any fibrous capsule that may have formed is not a problem during extraction, since instead of contracting onto the lead, it contracts onto the flexible coating which can be extracted out of the tight capsule.

Abstract: An implantable lead includes a distal portion carrying a tissue-stimulating electrode having an outer surface and an inner surface, at least a portion of the outer surface of the electrode being adapted to stimulate cardiac tissue. At least one of the surfaces of the stimulating electrode includes an overlay of a sulfonated thermoplastic elastomer/rubber for minimizing adhesion and tissue ingrowth while passing sufficient electrical current to stimulate the tissue. The overlay may comprise a coating, film, tube, sleeve or other encapsulation. Sulfonated block copolymers of styrene-ethylene-butylene-styrene (SEBS), styrene-ethylene-propylene-styrene (SEPS), styrene-isoprene-styrene and styrene-isobutylene-styrene are effective to inhibit the formation of thrombus at the shocking electrode. In addition, when these copolymers absorb body fluids, they swell and infiltrate the interstices of the electrode coils thereby inhibiting tissue ingrowth.

Abstract: A weak, positive electric charge is induced at the distal or discharge end of an infusion catheter to inhibit tissue ingrowth relative to the discharge opening. The charge may be induced by connecting an electrode carried at the distal end to a suitable source of electric potential. Alternatively, a positively charged member or coating may be provided at the distal end of the catheter.

Abstract: An implantable medical lead for use with an implantable cardioverter defibrillator, a method of manufacture and a system employing the lead and cardioverter/defibrillator in combination. The lead is provided with an elongated insulative lead body carrying a cardioversion/defibrillation electrode, which includes a first portion displaying essentially equal attenuation of positive and negative voltage pulses and a second portion displaying differential attenuation of positive and negative voltage pulses. The cardioveter/defibrillator provides a biphasic pulse in which a higher amplitude phase of the pulse is differentially attenuated by the electrode. The electrode is fabricated in whole or in part of a valve metal such as tantalum, anodized and annealed to provide a thick, durable oxide coating.

Abstract: An implantable medical device formed from a drawn refractory metal and having an improved biocompatible surface is described. The method by which the device is made includes coating a refractory metal article with platinum by a physical vapor deposition process and subjecting the coating article to drawing in a diamond die. The drawn article can be incorporated into an implantable medical device without removing the deposited metal.

Abstract: An implantable medical device has a pulse generator for generating electrical pulses, an electrical energy storage element connectable to an output stage, and an electrode arrangement for conducting the electrical pulses to tissue, the electrode arrangement having an input end and an output end. The output means of the pulse generator is connectable to the input end of the electrode arrangement, and the capacitance of the output stage is less than 1 .mu.F and the electrode arrangement has a capacitor with a capacitance greater than 1 .mu.F.

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: An implantable lead for use with an implantable pacemaker/cardioverter/defibrillator. Since irradiation from a radioisotope source is capable of inhibiting the growth of hyperproliferating cells as compared with normal cells, a radioisotope material which is incorporated into the lead can be used to decrease the rate of fibrotic growth. The radioisotope may be located inside the lead, alloyed into the metal from which the lead electrode or conductor is made, molded into rubber portions of the lead, or coated onto the conductor or electrode's surface. Beta emitting radioisotopes would be best suited as a radioactive material because of their comparatively short range of action within human tissue.

Abstract: The invention relates to an improved stimulation electrode for cardiac pacing and defibrillating, methods of manufacturing same, and methods of using same. Specifically, the electrodes of the invention by virtue of the methods of manufacturing and using, demonstrate improved capabilities of stimulating and sensing neuromuscular tissues. The electrodes have enhanced electrically-accessible surface areas which are coated with oxides of valve metals.

Abstract: Thrombosis in a blood vessel is prevented in a patient's body by the steps of positioning an electrically conductive member in an expanded portion of the blood vessel, at a site where the body is exposed to blood platelets, and disposing an electronegative potential generator in or adjacent to the patient's body and connected to the conductive member for maintaining a negative bias on the conductive member. One form of generating the negative bias is by passing microwaves through the patient's body to contact an embedded diode which generates the negative potential. The current density is maintained at about 50 milliamps per square centimeter.

Abstract: A stimulation electrode having a porous surface coating whose active surface area is significantly greater than the surface area defined by the geometric shape of the electrode, wherein the surface coating comprises an inert material, i.e. a material having no or only a very slight oxidation tendency, wherein the material of the surface coating is formed from an inert element, an inert chemical compound and/or an inert alloy, and the active surface area, by virtue of its fractal-like geometry, is greater by a factor of at least one thousand than the surface area defined by the basic geometric shape of the electrode.

Abstract: In an implantable defibrillator electrode having a large surfaced electrode in the form of a netting, a spiral, or a fabric of electronically conductive material or having an intracardial electrode in the form of a coil of electronically conductive material, the electrode is completely embedded in a biocompatible, hydrophilic, electrolytically conductive polymer or is covered by such a polymer.

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: The invention relates to implantable devices and materials, in which at least one part of the surface is provided with a tissue-plasminogen activator (t-PA). In this way, inflammatory reactions of the body and the formation of fibrous capsules, which ordinarily occur after implantation, are avoided or reduced.

Abstract: An electrode device for intracorporeal tissue stimulation, such as for intracardiac stimulation of heart tissue, includes an electrode cable containing at least one elongated, insulated conductor, and terminating in an electrode head at the distal end of the cable. The electrode head has a surface layer, which defines the shape of the electrode head, formed entirely of electrically conductive material, connected to the conductor, and thereby forming at least one stimulation surface. The surface layer is partially coated with high-resistivity insulating material, the coating forming a layer which is so thin that the difference in the distance between the uncovered portion of the stimulation surface and the heart tissue, and the distance between the insulating coating and the heart tissue, when the electrode device is applied to heart tissue, does not affect the threshold value for tissue stimulation.

Abstract: A pacing lead having a porous electrode of platinum-iridium with recessed areas or grooves formed into the surface. The grooves allow for acute electrode stabilization as a result of clot formation and endocardial tissue capture during insertion and immediate immobilization upon implant. At least one layer of a porous coating of 20-200 micron diameter spherical particles are deposited on the surface of the base electrode to obtain a porous macrostructure for promoting chronic tissue ingrowth. Additionally, a microstructure surface coating is applied to increase the active surface area and enhance electrical efficiency by lowering electrochemical polarization and increasing electrical capacitance.

Abstract: A small diameter, unipolar or bipolar, atrial or ventricular transvenous or epimyocardial pacing lead with a porous, platinized, steroid eluting cathode electrode exhibiting an effective surface area in the range of 0.1 to 4.0 mm.sup.2, preferably 0.6 to 3.0 mm.sup.2, provides low stimulation thresholds in the range of 0.5 volts, 0.5 milliseconds, very high pacing impedance (800 to 2,000 .OMEGA.), relatively low polarization, good to excellent sensing, and adequately low source impedance. The high pacing impedance prolongs the longevity of pacing pulse generators and allows for the miniaturization of their components. The low thresholds allow large safety factors at low applied voltages, which also contribute to increased battery longevity.

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.