Abstract: An implantable medical device includes a lead body having a distal end and a proximal end, a lumen and at least one lead wire extending through the lumen. The lead wire has an outer surface and a polymeric coating on at least a portion of the outer surface of the lead wire. The coating includes a first structure having a first end proximate the outer surface of the lead wire and a second end opposite the first end. The second end is movable relative to the first end and relative to the lead wire.

Abstract: A method of forming a lead includes providing an elongated lead body defining an annular groove disposed around a circumference of the lead body along one of a distal end or a proximal end of the lead body. A pre-contact is disposed around the circumference of the lead body within the annular groove. The pre-contact includes a pre-contact body having opposing first and second ends and first and second tabs extending outwardly from the opposing first and second ends, respectively. The first and second tabs are crimped together and folded flat against an outer surface of the pre-contact body. A polymeric material of the lead body is re-flowed to facilitate coupling of the pre-contact to the lead body. An outer surface of the pre-contact body is ground down to form a contact disposed along the one of the distal end or the proximal end of the lead body.

Abstract: A lead configured to be implanted into a patient's body comprises a lead body and a conductive filer positioned within the lead body and having a distal portion. An electrode is electrically coupled to the lead body and comprises a stimulation portion, a bobbin, and at least one coil of wire wound on the bobbin and electrically coupled between the stimulation portion and the distal end region to form an inductor between the distal end region and the stimulation portion.

Abstract: Exemplary techniques, devices, and systems relating to implantable medical devices (IMDs) and IMD features pertaining to imaging and charge induction are described. One IMD includes means for receiving a first signal relating to a magnetic resonance imaging process. The IMD further includes means for generating a second signal effective to reduce or cancel charge induced upon a lead of the IMD by the magnetic resonance imaging process.

Abstract: A medical implantable lead of the type being adapted to be implanted into a human or animal body and attached with a distal end to an organ inside the body, has a helix of a helical wire in the distal end which is adapted to be screwed into the organ. In addition to the first helix, the lead also has a second helix of a helical wire, the second helix having the same diameter, the same pitch and being intertwined with the helical wire of the first helix and which, upon rotation of the first helix, will be rotated and screwed into the tissue. The first helix is electrically non-conductive whereas the second helix is electrically conductive. In a method for attaching a medical implantable lead to an organ inside a human or animal body, such a medical lead is employed and fixed to tissue in vivo.

Abstract: An implantable active fixation lead includes an outer sheath, a protector member having a peripheral surface extending between its distal and proximal end surfaces with a helical groove formed in the peripheral surface, and a fixation helix integral with the outer sheath. The fixation helix includes a tip end engageable with body tissue and slidably engaged with the helical groove for relative translation and rotation. A longitudinal force on the lead firmly engages the protector member's distal end surface with the body tissue. With the fixation helix initially retracted proximally of the protector member's distal end surface and disengaged from the body tissue, upon application of torque to the outer sheath, the distal end surface of the protector member is moved proximally with respect to the fixation helix which, simultaneously, is extended distally beyond the distal end surface of the protector member to an extended position into engagement with the body tissue.

Abstract: A connector for an implantable medical lead that is electrically and mechanically connectable to an implantable medical device, has a connector pin made of a first conducting material. A tubular insulator made of an insulating material concentrically surrounds at least a portion of the pin. A connector ring made of a second conducting material is concentrically positioned around at least a portion of the insulator. The insulator is connected to the connector ring by spark plasma sintering in the case of an active fixation lead, and is connected to the ring and the pin by spark plasma sintering in the case of a passive fixation lead.

Abstract: An injection device including a syringe connectable to a corkscrew injection needle via an adapter is disclosed. The corkscrew needle includes a proximal end and a distal end and a bore formed through the proximal and distal ends, the corkscrew needle terminating with a sharpened tip at the distal end. The syringe includes a barrel and a chamber formed therein for containing an injectable substance. The barrel includes a proximal end, a distal end, and an outlet at the distal end in fluid communication with the chamber. The distal end of the syringe connects to the proximal end of the adapter. The adapter bore provides fluid communication between the syringe and the corkscrew needle. The proximal end of the corkscrew needle is rotatably coupled to distal end of the adapter which allows rotation of the corkscrew needle without rotating the syringe.

Abstract: A method for manufacturing a lead includes pre-forming at least one relief section along a length of an elongated conductor having a first end and an opposing second end. The conductor with the pre-formed relief section is inserted into a conductor lumen defined along a length of an elongated lead body. The lead body has a first end and an opposing second end. An electrode is disposed at the first end of the lead body. The first end of the conductor is electrically coupled to the electrode. A terminal is disposed at the second end of the lead body. The second end of the conductor is electrically coupled to the terminal.

Abstract: An electrical lead for a cardiac device includes a body having a distal end sized for insertion through a catheter, first and second electrodes extending through the body, with each electrode terminating in a tip having proximal and distal ends and arranged to extend to an area of cardiac tissue. The tips include a fully insulated portion on the proximal and distal ends measuring in a range between 5 percent and 40 percent of the lengths of the tips, and further include an uninsulated intermediate section. The tip of the second electrode includes a helical section surrounding the first electrode and has an insulated portion on an inwardly facing portion surface facing toward the first electrode. The tip of the second electrode also includes a fully insulated portion on the proximal and distal ends measuring in the same or similar percentage range.

Abstract: A retractable screw-type stimulation or defibrillation intracardiac lead is disclosed. According to one embodiment, the lead comprises a flexible hollow sheath (12) having at its distal end a lead head (10) and a connector (66) at its proximal end. The connector comprises a pin (62) connected to a lead head electrode (18). The lead head comprises a tubular body (28), at least one electrode (18, 20) for stimulation or defibrillation, a moving element translationally and rotationally moving within the tubular body in a helical motion, an anchoring screw (24) axially moving with respect to the tubular body, and a deployment mechanism (22) to deploy the anchoring screw out of the tubular body (28).

Abstract: A leadless cardiac pacemaker comprises a housing, a plurality of electrodes coupled to an outer surface of the housing, and a pulse delivery system hermetically contained within the housing and electrically coupled to the electrode plurality, the pulse delivery system configured for sourcing energy internal to the housing, generating and delivering electrical pulses to the electrode plurality. The pacemaker further comprises an anti-unscrewing feature disposed on either a fixation device of the pacemaker or on the housing itself. The anti-unscrewing feature can be configured to prevent the fixation device from disengaging the wall of the heart.

Abstract: A heat dissipating housing to be positioned at a distal end of a stimulation/defibrillation lead, the housing including a housing body having a distal contact face at a distal end, an inner wall, and an outer wall. The housing further includes an anchoring screw, wherein at least a portion of the anchoring screw extends axially from the distal end of the housing body. The anchoring screw is configured to secure the distal contact face in contact with tissue of a patient to form a thermal bridge between the tissue and the housing body. The housing body is electrically insulated and thermally conductive to dissipate heat transferred through the thermal bridge to the outer wall of the housing body.

Abstract: Described is an implantable lead comprising a flexible body extending between a proximal end and a distal end and a distal assembly coupled to the distal end of the body. The distal assembly includes a housing having a distal end and a proximal end, the proximal end fixedly coupled to the distal end of the lead body, a coupler rotatably disposed within the housing, the coupler having a proximal end and a distal end, and a helical electrode fixedly secured to the distal end of the coupler. The helical electrode comprises a proximal axial length portion that comprises a non-degradable material, and a distal axial length portion that comprises a biodegradable material. The coupler and the helical electrode are configured to rotate and therefore translate relative to the housing.

Abstract: Implantable leadless pacing devices and medical device systems including an implantable leadless pacing device are disclosed. An example implantable leadless pacing device may include a pacing capsule. The pacing capsule may include a housing. The housing may have a proximal region and a distal region. A first electrode may be disposed along the distal region. An anchoring member may be coupled to the distal region. One or more anti-rotation members may be fixedly attached to the distal region.

Abstract: An implantable leadless cardiac pacing device and associated delivery and retrieval devices. The implantable device includes a docking member extending from the proximal end of the housing of the implantable device configured to engage with the delivery and/or retrieval device to facilitate delivery and/or retrieval of the implantable leadless cardiac pacing device.

Abstract: A delivery system for implanting a leadless cardiac pacemaker into a patient is provided. The cardiac pacemaker can include a docking or delivery feature having a through-hole disposed on or near a proximal end of the pacemaker for attachment to the delivery system. In some embodiments, the delivery catheter can include first and second tethers configured to engage the delivery feature of the pacemaker. The tethers, when partially aligned, can have a cross-sectional diameter larger than the through-hole of the delivery feature, and when un-aligned, can have a cross-sectional diameter smaller than the through-hole of the delivery feature. Methods of delivering the leadless cardiac pacemaker with the delivery system are also provided.

Abstract: A fixation member of an electrode assembly for an implantable medical device includes a tissue engaging portion extending along a circular path, between a piercing distal tip thereof and a fixed end of the member. The circular path extends around a longitudinal axis of the assembly. A helical structure of the assembly, which includes an electrode surface formed thereon and a piercing distal tip, also extends around the longitudinal axis and is located within a perimeter of the circular path. The tissue engaging portion of the fixation member extends from the distal tip thereof in a direction along the circular path that is the same as that in which the helical structure extends from the distal tip thereof. The electrode assembly may include a pair of the fixation members, wherein each tissue engaging portion may extend approximately one half turn along the circular path.

Abstract: Exemplary systems for loading a pre-curved electrode array onto a stylet include a loading tool and a stylet retainer. The loading tool includes a docking assembly comprising a plurality of wing members that form a receptacle configured to receive a proximal portion of the stylet, a channel assembly comprising a channel configured to receive and allow passage therethrough of the pre-curved electrode array, the channel further configured to receive a distal portion of the stylet, and a connecting member configured to connect the channel assembly to the docking assembly. The stylet retainer is configured to couple to the loading tool to retain the stylet within the loading tool while the pre-curved electrode array is loaded onto the stylet. Corresponding methods are also described.

Abstract: Methods, devices and assemblies for anchoring implanted medical electrical leads employed in the stimulating and/or sensing of signals in tissue are disclosed. The devices include a lead anchoring clip having a central hub portion, an anchoring portion for coupling to tissue and a lead engagement mechanism that couples the clip to a medical electrical lead.

Abstract: Devices or methods such as for stimulating excitable tissue or sensing physiologic response or other signals that can use chronic fixation mechanism are described. An implantable apparatus can comprise an electrostimulation electrode assembly that can include a primary fixation member and a secondary fixation member. The primary fixation member can be actively engaged or affixed to a target tissue of a patient, and the second fixation member can be biased against the target tissue, collapsed or compressed against the target tissue when the primary fixation member is affixed to the target tissue. The electrostimulation electrode assembly can also include at least one electrode such as to contact heart or other excitable tissue such as to deliver chronic electrostimulation or sensing physiologic responses.

Abstract: Described is an implantable lead comprising a flexible body extending between a proximal end and a distal end and a distal assembly coupled to the distal end of the body. The distal assembly includes a housing having a distal end and a proximal end, the proximal end fixedly coupled to the distal end of the lead body, a coupler rotatably disposed within the housing, the coupler having a proximal end and a distal end, and a helical electrode fixedly secured to the distal end of the coupler. The helical electrode comprises a proximal axial length portion that comprises a non-degradable material, and a distal axial length portion that comprises a biodegradable material. The coupler and the helical electrode are configured to rotate and therefore translate relative to the housing.

Abstract: Exemplary loading tools configured to facilitate loading of a pre-curved electrode array onto a stylet include a docking assembly, a channel assembly, and a connecting member configured to connect the channel assembly to the docking assembly and maintain a distance therebetween. The docking assembly is configured to couple to the stylet. The channel assembly includes a channel configured to receive and allow passage therethrough of the pre-curved electrode array. The channel is aligned with the docking assembly such that when the stylet is coupled to the docking assembly, the stylet is located at least partially within the channel.

Abstract: A medical implantable lead has a header in a distal end, a fixation arrangement and an electrode arranged in the header. The lead also has a connector in a proximal end that includes a connector pin and is adapted to be connected to a monitoring and/or controlling device, and an inner coil, which extends inside an outer casing of the lead and is adapted to transmit electrical signals between the monitoring and/or controlling device and the electrode. The inner coil is attached to the connector pin. The inner coil extends through a bore inside the connector pin and is attached to the connector pin in its proximal end. A method for manufacturing such a lead is also provided.

Abstract: A medical implantable lead comprises a conduction controlling means, which at least during an initial stage after implantation is capable of rendering a first contact surface electrically inactive and which is capable of rendering the first contact surface electrically active after the initial stage. By means of the inventive lead it is possible to detect whether the helix is sufficiently screwed into the tissue or not.

Abstract: A system and method for implantation of an autonomous intracardiac capsule. The autonomous capsule includes a cylindrical body with an anchoring screw for penetrating a tissue wall, and at least one coupling finger radially projecting outwards. An implantation accessory includes a lead body and a helical guide, for guiding and driving by rotation the capsule. This helical guide is integral with the lead body, and its inner diameter is sufficient to contain that cylindrical body of the capsule therein. The helix direction of the helical guide is opposite to that of the anchoring screw such that continued rotational motion imparted on the lead body drives the anchoring screw into the target tissue and then emerges the capsule from the helical guide. The helical guide is resiliently compressible in axial direction, and its helix pitch is increased in the free distal end portion.

Abstract: A transvenously implantable medical device (TIMD) includes an electrical lead and a control module. The electrical lead includes one or more electrodes and is adapted for transvenous implantation. The electrical lead is also pre-biased to expand from a collapsed state to an expanded state to mechanically engage an internal wall of a blood vessel. The control module is secured to and in electrical communication with the electrical lead. The control module includes a signal management component and a power component disposed in a housing adapted for implantation into the blood vessel. The control module is adapted for at least one of stimulating and sensing a physiologic response using the one or more electrodes of the electrical lead.

Abstract: A temporary implantable medical device lead includes a connector configured to connect the lead to an external control module, a helically coiled conductor including a plurality of insulated filars and having a proximal end mechanically and electrically connected to the connector, and one or more electrodes defined by uninsulated portions of the helically coiled conductor. The temporary implantable medical device lead also includes one or more tine assemblies proximal to the one or more electrodes and configured to inhibit axial migration of the temporary implantable medical device lead, each tine assembly including a base and a plurality of tines extending from the base.

Abstract: An active bipolar cardiac electrical lead includes a helical anchor electrode, a tip electrode pin, an intermediate connection mount, a ring electrode, and a tip housing. The tip electrode pin engages an inner conductor coil at a proximal end and engages a proximal end of the helical anchor electrode at a distal end. The intermediate connection mount defines an axial lumen therethrough, a proximal fitting, a cylindrical flange, and a distal fitting. The ring electrode has an exposed section that sleeves over and connects with the proximal fitting of the intermediate connection mount and has a proximal sleeve that engages with an outer conductor coil and an outer sheath of the lead. The tip housing defines an axial bore that houses the helical anchor electrode and a distal portion of the tip electrode pin. A proximal portion of the tip electrode pin is housed within the axial lumen of the intermediate connection mount.

Abstract: An implantable lead may have a distal assembly including a coupler and a fixation helix secured to the coupler. The fixation helix may be formed of a filar having a non-circular cross-sectional profile having a major dimension and a minor dimension. The major dimension may be disposed transversely to a longitudinal axis of the fixation helix.

Abstract: An implantable medical lead comprises an insulating tubing with a channel housing a conductor electrically connected to a shaft present in a lumen of a bearing. The shaft is also connected to a fixation helix present in a lumen of a lead header. A clot-inducing structure of a thrombogenic material is present in a distal portion of the channel and/or in the lumen of the bearing to trigger formation of a clot when blood enters the implantable medical lead and thereby inhibit blood from entering further into the channel.

Abstract: An electrode connection for an electrode catheter including an electrode, a line for electrical signals configured as a coil having an electrode end connected to the electrode, and a fixation device for the electrode end of the coil on the electrode, wherein the fixation device includes an inner sleeve, on which the electrode end of the coil sits, and a squeeze ring, which acts upon the electrode end of the coil, establishing an electrical contact with the electrode and mechanical clamping on the inner sleeve.

Abstract: A transvenously implantable medical device (TIMD) includes an electrical lead and a control module. The electrical lead includes one or more electrodes and is adapted for transvenous implantation. The electrical lead is also pre-biased to expand from a collapsed state to an expanded state to mechanically engage an internal wall of a blood vessel. The control module is secured to and in electrical communication with the electrical lead. The control module includes a signal management component and a power component disposed in a housing adapted for implantation into the blood vessel. The control module is adapted for at least one of stimulating and sensing a physiologic response using the one or more electrodes of the electrical lead.

Abstract: A leadless intra-cardiac medical device (LIMD) includes a housing configured to be implanted entirely within a single local chamber of the heart.

Abstract: An assembly for introducing a leadless intra-cardiac medical device includes a sheath having an internal passage, wherein the sheath is configured to be maneuvered into the heart of the patient. A housing may be retained within the internal passage, wherein the housing is configured to be pushed out of the sheath, the housing having a first anchoring member configured to anchor the housing to a first implant location within the heart. The assembly may also include an electrode trailing the housing within the internal passage, wherein the electrode is also configured to be pushed out of the sheath. The electrode has a second anchoring member configured to anchor the electrode to a second implant location within the heart. A conductive wire connects the housing to the electrode, wherein movement of the housing out of the sheath causes the electrode to follow the movement to a distal end of the sheath.

Abstract: A medical electrical lead having an elongated lead body and a fixation helix extending along a generally helical axis, mounted around the outer circumference of the lead body. The fixation helix has a free end spaced from and extending from the lead body for less than the circumference of the lead body. The lead body includes an additional component which provides a rotation stop extending from the outer circumference of the lead body and provides stop surface generally perpendicular to the axis of the helix.

Abstract: Bioelectric implants are provided in three distinct embodiments, namely a bone/tissue anchor, a suture construction, and a plate. The bioelectric implants function in dual capacities as both fixation devices, and as galvanic cells for the production of electrical energy used for therapeutic purposes in tissue regeneration and healing. The bioelectric anchor may take the general form of a screw or pin having a hollow interior or cavity that extends through the body of the anchor. A coating can be applied to the cavity to form the anode portion of the galvanic cell. The outer surface of the anchor serves as a cathode. Bodily fluids and tissue act as an electrolyte to facilitate the chemical reactions necessary for the galvanic cell. For the suture construction, one or more strands of material are the cathode, and one or more strands of peripheral surrounding material act as the anode. Bodily fluids/tissue in contact with the suture act as an electrolyte.

Abstract: A method for implanting an active fixation medical lead is disclosed herein. The lead may include a lead body distal end, a tissue fixation helical anchor and a structure. The tissue fixation helical anchor may be coupled to the lead body distal end and include a distal tip. The structure may be coupled to the lead body distal end and include a structure distal end including a first radiopaque marker. The structure may be biased to project the structure distal end near the distal tip. When the tissue fixation helical anchor is progressively embedded in the cardiac tissue, the cardiac tissue progressively displaces the structure distal end proximally.

Abstract: An implantable therapy lead includes a tubular body, an obturator, and a helical anchor electrode. The obturator is displaceably supported on a distal end of the tubular body between a recessed position and an extended position. When the obturator is in the extended position, the extreme distal tip of the tissue penetrating point of the helical anchor electrode contacts an outer surface of the obturator in a manner that prevents the extreme distal tip from being capable of tissue penetration significant enough to allow the helical anchor electrode to be screwed into the heart tissue. When the obturator is in the recessed position, the extreme distal tip no longer contacts the outer surface of the obturator and the extreme distal tip is positioned relative to the outer surface of the obturator so as to allow the extreme distal tip to penetrate the heart tissue.

Abstract: An implantable cardiac stimulation lead for implantation along the septal wall and/or the free wall of the left ventricular is disclosed. The lead is a microlead formed in its distal portion by a microcable with an active portion comprising a series of exposed areas forming the stimulation electrodes. This lead is implanted by an accessory with a needle having a puncture pointed free end and an opposite end mounted on a gripping end tip, and a releasable device for holding the microcable along the length of the needle. The microlead is introduced by injection of the microcable with penetration of the needle into the wall thickness of the interventricular septum or in the thickness of the free wall of the left ventricle, below the surface and along this wall between the apex region the atrial region.

Abstract: A stimulation lead is disclosed. This lead comprises a lead body having a lumen housing an inner conductor, the conductor being axially and rotationally movable within the lumen, and coupled to a generator of an active implantable medical device. The lead also has a helical anchoring screw extending from a distal end configured to penetrate target tissue, and a stimulation needle electrically coupled to the conductor and comprising at its distal end an active free portion with at least one stimulation electrode for application of pacing pulses to the target tissue. The stimulation needle is axially movable between a retracted position inside the tubular body, and a deployed position with the active free portion of the needle emerging out of the tubular body, utilizing an actuating mechanism for moving the needle from its retracted position to its deployed position under the effect of rotary movement relative to the lead body.

Abstract: An implantable medical electrical lead includes an extendable/retractable active fixation distal tip assembly. The distal tip assembly includes a shell having an internal cavity and a helix guide member extending at least partially across the cavity and including an axial surface. The distal tip assembly also includes a rotatable coupler within the cavity and a fixation helix fixedly attached to the coupler. The fixation helix engages the helix guide member such that rotation of the coupler and the fixation helix causes the coupler and the fixation helix to advance distally relative to the shell. The coupler further includes a distal rotation stop member protruding axially from the coupler configured to abut the axial surface of the helix guide member to delimit rotation and extension of the coupler and the fixation helix.

Abstract: An implantable active fixation cardiac lead is disclosed that includes an elongated lead body having opposed proximal and distal end portions and having an interior lumen extending therethrough, an axially rotatable extendable and retractable fixation helix operatively associated with the distal end portion of the lead body, a rotatable in-line quadripolar connector assembly operatively associated with the proximal end portion of the lead body and including an elongated rotatable pin electrode having opposed proximal and distal end portions, and an elongated torque transmitting conductor coil extending through the interior lumen of the lead body and having a proximal end portion connected to the distal end portion of the rotatable pin electrode and a distal end portion connected to the rotatable fixation helix, to facilitate manual activation of the fixation helix.

Abstract: In a medical implantable lead and method for monitoring and/or controlling of an organ inside a human or animal body, the lead has a helix in a distal end that is rotatable by an inner wire coil (5), which is disposed inside of and along essentially the entire length of the lead and which is rotatably arranged in relation to an outer sleeve, such that the helix is attachable to the organ by being screwed into the tissue inside the body. The lead is provided with a connector in a proximal end which is connectible to an electronic device for monitoring or controlling the function of the organ, the connector having a connector pin that is in engagement with the wire coil and that is rotatably journaled inside a connector housing. During mounting of the medical implantable lead to the organ, the inner wire coil is rotatable by rotating the connector pin in relation to the connector housing with a suitable tool. The connector is provided with a friction brake between the connector pin and the connector housing.

Abstract: A single-pass pacing lead capable of sensing and pacing both the atria and the ventricles is described. In some examples, the single-pass pacing lead is connected to a DDD pacemaker. In some examples, the single-pass pacing lead comprises four electrodes. In some examples, the lead includes three electrodes configured to be positioned in or near an atrium, e.g., the right atrium, and one electrode configured to be positioned in or near a ventricle, e.g., the left ventricle, when the lead is implanted. In other examples, the lead includes two electrodes configured to be positioned in each of the atrium and ventricle when the lead is implanted. In some examples, one of the electrodes, which is configured to be positioned proximate the coronary sinus ostium when the lead is implanted, comprises a helical element for fixation of the lead to tissue.

Abstract: An intracorporeal autonomous active medical device having a capsule body and a base. The capsule body includes a body portion and a lid portion, and the capsule body contains therein electronic circuitry containing the active elements of the autonomous medical device, and a power supply. The capsule body also includes a fastening system on an exterior surface of the capsule body that is configured to correspond with a fastening mechanism on the base configured to be anchored to a tissue wall. The fastening mechanism provides selective engagement between the capsule body and the base.

Abstract: Disclosed herein are a variety of implantable medical leads for coupling to an implantable pulse generator and targeted stimulation of the lateral and posterior basal left ventricular region of a patient heart. As one example, the lead may include a tubular body including proximal section, an intermediate section and a distal section. The intermediate section biases into a generally S-shaped or sinusoidal-shaped configuration when the intermediate section is in a free or non-restricted state. The proximal section proximally extends from the intermediate section to a proximal end configured to electrically couple to the implantable pulse generator. The distal section biases into a generally straight linear shaped configuration when the distal section is in a free or non-restricted state.

Abstract: An active fixation lead may have a lead body formed at least in part from an inner member and an outer sheath. The inner member may include a pace/sense lumen and one or more cable lumens. The inner member may include one or more longitudinally extending crumple zones that are configured to reduce stress within the pace/sense lumen that could otherwise be caused by compressive forces applied to the lead.

Abstract: An implantable medical lead of the invention comprises an electrically active helix electrode extendable and retractable relative to a distal tip of the lead, an electrically conductive mapping collar disposed at the lead's distal tip and a proximal end carrying an electrical connector assembly. The electrical connector assembly comprises a first terminal connected to the helix electrode and a second terminal separately connected to the mapping collar. An advantage of the independent helix electrode and mapping collar circuits is that the implanting physician can confirm from separate electrode impedance readings that the helix is in fact extended and fully embedded within the myocardium. Further, the independent mapping collar and helix electrode circuits may be used, in conjunction with a configurable or programmable switch network, to provide the implanting physician with a choice of electrode impedances.

Abstract: A delivery system for implanting a leadless cardiac pacemaker into a patient is provided. The cardiac pacemaker can include a docking or delivery feature having a through-hole disposed on or near a proximal end of the pacemaker for attachment to the delivery system. In some embodiments, the delivery catheter can include first and second tethers configured to engage the delivery feature of the pacemaker. The tethers, when partially aligned, can have a cross-sectional diameter larger than the through-hole of the delivery feature, and when un-aligned, can have a cross-sectional diameter smaller than the through-hole of the delivery feature. Methods of delivering the leadless cardiac pacemaker with the delivery system are also provided.