Abstract: An implantable device includes a device body and at least one anchoring unit configured and arranged for anchoring the device body in a patient upon implantation. The anchoring unit includes a resorbable material that resorbs into the patient over a period of time after implantation.

Abstract: A power supply for an implantable cardioverter-defibrillator for subcutaneous positioning between the third rib and the twelfth rib and using a lead system that does not directly contact a patient's heart or reside in the intrathoracic blood vessels and for providing anti-tachycardia pacing energy to the heart, comprising a capacitor subsystem for storing the anti-tachycardia pacing energy for delivery to the patient's heart; and a battery subsystem electrically coupled to the capacitor subsystem for providing the anti-tachycardia pacing energy to the capacitor subsystem.

Abstract: A resuscitation system for use by a rescuer for resuscitating a patient having a ventricular arrhythmia, comprising circuitry and processing configured for detection of chest compression/phase timing information indicative of the start of the decompression phase, circuitry and processing configured for delivery of electromagnetic therapy for the termination of ventricular arrhythmias, wherein the circuitry and processing for the delivery of electromagnetic therapy utilizes the chest compression phase timing information to initiate delivery of the electromagnetic therapy within 300 milliseconds of the start of the decompression phase.

Abstract: A subcutaneous cardiac device includes a subcutaneous electrode and a housing coupled to the subcutaneous electrode by a lead with a lead wire. The subcutaneous electrode is adapted to be implanted in a frontal region of the patient so as to overlap a portion of the patient's heart. The subcutaneous electrode is configured for therapy delivery in combination with one or both of the housing or a second subcutaneous electrode.

Abstract: A method for reducing left ventricular volume, which comprises identifying infarcted tissue during open chest surgery; reducing left ventricle volume while preserving the ventricular apex; and realigning the ventricular apex, such that the realigning step comprises closing the lower or apical portion of said ventricle to achieve appropriate functional contractile geometry of said ventricle in a dyskinetic ventricle of a heart.

Abstract: Devices and methods of use for introduction and implantation of an electrode as part of a minimally invasive technique. An implantable baroreflex activation system includes a control system having an implantable housing, an electrical lead, attachable to the control system, and an electrode structure. The electrode structure is near one end of the electrical lead, and includes a monopolar electrode, a backing material having an effective surface area larger than the electrode, and a releasable pivotable interface to mate with an implant tool. The electrode is configured for implantation on an outer surface of a blood vessel and the control system is programmed to deliver a baroreflex therapy via the monopolar electrode to a baroreceptor within a wall of the blood vessel.

Abstract: The intrapericardial lead includes a lead body having a proximal portion and a flexible, pre-curved distal end portion. The distal end portion carries at least one electrode assembly containing an electrode adapted to engage pericardial tissue. The distal end portion further carries a pre-curved flexible wire member having ends attached to spaced apart points along the distal end portion of the lead body, the flexible wire member having a normally expanded state wherein an intermediate portion of the wire member is spaced apart from the distal end portion, and a generally straightened state wherein the wire member and the distal end portion are disposed in a more parallel, adjacent relationship so as to present a small frontal area to facilitate delivery into the pericardial space. The wire member re-expands to its normal state after delivery into the pericardial space to anchor the distal end portion of the lead body relative to the pericardial tissue.

Abstract: The present invention provides methods for generating relevant in vitro models of engineered innervated tissue, as well as uses of such tissues.

Abstract: A medical device is disclosed for implantation on an epicardial surface of the heart. The device has a transmural member providing optimal electrode locations for various therapies. The hemodynamically optimal therapy is guided by sensed left ventricular pressure and electrical activity. The device may be used alone or with a companion implanted cardiac rhythm management device.

Abstract: A delivery apparatus for accessing the pericardial space of a heart including an elongated body defining a lumen and a piercing member that extends from a distal portion of the elongated body for piercing tissue of the heart. A spring expands from a distal end of the piercing member in response to the distal end of the piercing member passing through the tissue and into the pericardial space. An electrode located on the spring in order to sense signals indicative of a distal end of the spring passing through the tissue and into the pericardial space.

Abstract: Methods and devices for implanting pacing electrodes or other apparatus, or for delivering substances, to the heart of other tissues within the body. A guided tissue penetrating catheter is inserted into a body lumen (e.g., blood vessel) or into a body cavity or space (e.g., the pericardial space) and a penetrator is advanced from the catheter to a target location. In some embodiments, a substance or an apparatus (such as an electrode) may be delivered through a lumen in the penetrator. In other embodiments, a guidewire may be advanced through the penetrator, the penetrating catheter may then be removed and an apparatus (e.g., electrode) may then be advanced over that guidewire. Also disclosed are various implantable electrodes and electrode anchoring apparatus.

Abstract: One embodiment of the present invention provides a lead electrode assembly for use with an implantable cardioverter-defibrillator subcutaneously implanted outside the ribcage between the third and twelfth ribs comprising the electrode.

Abstract: A composite RF current attenuator for a medical lead includes a conductor having a distal electrode contactable to biological cells, a bandstop filter in series with the lead conductor for attenuating RF currents flow through the lead conductor at a selected center frequency or across a range of frequencies about the center frequency, and a lowpass filter in series with the bandstop filter and forming a portion of the lead conductor. The bandstop filter has a capacitance in parallel with a first inductance. In a preferred form, the lowpass filter includes a second inductance in series with the bandstop filter, wherein the values of capacitance and inductances for the composite RF current attenuator are selected such that it attenuates MRI-induced RF current flow in an MRI environment.

Abstract: An electromagnetic cardiac assembly adapted to assist ventricular output in a human heart includes a magnetic mat adapted for mounting inside a human body near the heart. The mat is made from a material responsive to application of an electromagnetic field so as to be movable into compressive relation with the heart in response to application of the electromagnetic field thereto and movable out of said compressive relation to permit the heart to relax when application of the electromagnetic field is discontinued. The assembly also includes an electromagnetic subassembly adapted for mounting on the human body in functionally cooperative relation with respect to the mat, and an energy dispersion device adapted for mounting between the mat and the heart. The energy dispersion device is constructed and arranged to disperse energy between the mat and the heart.

Abstract: An electromagnetic cardiac assembly adapted to assist ventricular output in a human heart includes a magnetic mat adapted for mounting inside a human body adjacent the heart. The mat is made from a material responsive to application of an electromagnetic field so as to be movable into compressive relation with the heart in response to application of the electromagnetic field thereto and movable out of said compressive relation to permit the heart to relax when application of said electromagnetic field is discontinued. The mat has a posterior surface that substantially conforms to an anterior surface of the heart without flexing the mat. The assembly also includes an electromagnetic subassembly adapted for mounting on the human body in functionally cooperative relation with respect to the mat, and for alternately generating and discontinuing the electromagnetic field so that the mat alternately moves into and out of the compressive relation with the heart.

Abstract: An electromagnetic biventricular assist device adapted to assist ventricular output in a human heart includes a magnetic mat adapted for mounting inside a human body adjacent the heart, and an electromagnetic assembly adapted for mounting on the human body in functionally cooperative relation with respect to the mat. The mat is responsive to application of a first electromagnetic field generated by the electromagnetic assembly so as to be movable from a neutral position towards the heart and into compressive relation with the heart, and responsive to application of a second electromagnetic field that is opposite the first electromagnetic field so as to be movable from the neutral position in a direction away from the heart to expand ventricles in the heart and augment filling of the ventricles. A control circuit is constructed and arranged to control when the first and second electromagnetic fields are generated by the electromagnetic assembly.

Abstract: The methods and apparatus for lead placement on a surface of the heart are employed using an elongated body having proximal and distal end portions. The body defines a lead receiving passageway extending between a proximal inlet and a distal outlet for receiving a lead therethrough for contact with the heart surface. The elongated body is adapted for insertion between a pericardium and an epicardial surface. At least a portion of the body may have a non-circular cross-sectional shape adapted to retain the body orientation between the pericardium and the epicardial surface.

Abstract: Medical lead systems utilizing electromagnetic bandstop filters are provide which can be utilized in a magnetic resonance imaging (MRI) environment for patients who have implanted medical devices. The medical lead system includes an implanted lead having at least one bandstop filter associated therewith, for attenuating current flow through the lead over a range of frequencies. The bandstop filter has an overall circuit Q wherein the resultant 3 dB bandwidth is at least 10 kHz. The values of capacitance and inductance of the bandstop filter are selected such that the bandstop filter is resonant at a selected center frequency. Preferably, the bandstop filter has an overall circuit Q wherein the resultant 10 dB bandwidth is at least 10 kHz. Such bandstop filters are backwards compatible with known implantable deployment systems and extraction systems.

Abstract: An implantable medical electrical lead for electrical stimulation of body tissue that includes at least one shape memory polymer portion that has a first configuration and a second configuration, wherein the second configuration is obtained upon exposure of the shape memory polymer portion to a transition stimulus, and wherein the second configuration of the modifiable portion exhibits a greater resistance to movement of the lead within the body tissue than does the first configuration; and at least one electrode configured to provide electrical stimulation of body tissue, wherein the lead has a proximal end and a distal end. Systems and kits as well as methods of utilizing the leads of the invention are also included.

Abstract: An epicardial patch includes an extracellular matrix (ECM) and a plurality of electrodes. The isolated ECM is configured for epicardial attachment over a myocardial region including an injured area to control post-injury remodeling of the myocardial region. The plurality of electrodes is configured for delivering electrical stimulation to enhance the effect of the isolated ECM in remodeling control by altering workload and stress on the myocardial region.

Abstract: A TENS currents application device has a composite laminated construction consisting of an electrical current conductive layer made of a carbon material sandwiched between a flexible outer layer and a body contact layer. The outer layer may be made of plastic or metal and has a plurality of magnet elements imbedded therein. A heating means may be additionally provided in the device. The device may be in the form of a disc or round ball which can be held in the palm of a patient or in the form of a sole insert which can be placed in the sole of a foot ware. Protruding points are additionally formed on the outer surface of the round ball and on the outer surface of the sole insert. A vibrating device is located in the handheld device for providing additional massaging function to enhance the TENS treatment.

Abstract: A pacing lead for implantation in the pericardial space includes an elongated lead body, a compression fixation element, and at least one electrode on either the lead body or the fixation element. The fixation element defines a resilient structure, and is positioned and dimensioned so that when the lead is disposed in the pericardial space, the resilient fixation element is compressed between the parietal and visceral pericardium, thereby biasing the electrode against the myocardium and providing positional stabilization to the lead. Further positional stability may be provided mechanically with structures enabling the application of adhesive or with fixation screw or tine elements.

Abstract: A cardiac harness for treating or preventing congestive heart failure is configured to be placed about at least a portion of a patient's heart so as to apply a mild compressive force on the heart. In one embodiment, the cardiac harness comprises a plurality of spaced apart conductive panels arranged so that there is no electrical continuity circumferentially around the harness. In an additional embodiment, a cardiac harness is provided that is insulated so as not to conduct electricity circumferentially about the harness.

Abstract: Devices and methods provide for ablation of cardiac tissue for treating cardiac arrhythmias such as atrial fibrillation. Although the devices and methods are often be used to ablate epicardial tissue in the vicinity of at least one pulmonary vein, various embodiments may be used to ablate other cardiac tissues in other locations on a heart. Devices generally include at least one tissue contacting member for contacting epicardial tissue and securing the ablation device to the epicardial tissue, and at least one ablation member for ablating the tissue. Various embodiments include features, such as suction apertures, which enable the device to attach to the epicardial surface with sufficient strength to allow the tissue to be stabilized via the device. For example, some embodiments may be used to stabilize a beating heart to enable a beating heart ablation procedure. Many of the devices may be introduced into a patient via minimally invasive introducer devices and the like.

Abstract: A method of delivering a myocardial infarction patch to a surface of a heart is disclosed herein. In one embodiment, the method includes deploying the patch from an intra pericardial lead.

Abstract: The intrapericardial lead includes a lead body having a proximal portion and a flexible, pre-curved distal end portion. The distal end portion carries at least one electrode assembly containing an electrode adapted to engage pericardial tissue. The distal end portion further carries a pre-curved flexible wire member having ends attached to spaced apart points along the distal end portion of the lead body, the flexible wire member having a normally expanded state wherein an intermediate portion of the wire member is spaced apart from the distal end portion, and a generally straightened state wherein the wire member and the distal end portion are disposed in a more parallel, adjacent relationship so as to present a small frontal area to facilitate delivery into the pericardial space. The wire member re-expands to its normal state after delivery into the percaridal space to anchor the distal end portion of the lead body relative to the pericardial tissue.

Abstract: A chamber or vasculature of a heart may be accessed via the pericardial space of the heart. Initially, the pericardial space may be accessed via a transmyocardial approach or a subxiphoid approach. A lead or other implantable apparatus may thus be routed into the pericardial space, through myocardial tissue and into the chamber or vasculature. The lead or other apparatus may be used to sense activity in or provide therapy to the heart.

Abstract: An implantable cardiac patch is configured to be joined to a surface of a heart and includes a body portion having an inner surface configured to be joined to the surface of the heart. The body portion also has a plurality of pores extending into the body portion from the inner surface. A plurality of electrodes are attached to the body portion such that the electrodes are positioned proximate the surface of the heart, and a lead is electrically connected to the electrodes at a connecting portion of the lead. The lead has a proximal end configured for joining to an implantable device.

Abstract: Methods and apparatus for cardiac pacing, cardioversion and defibrillation rely on delivering ultrasonic or other vibrational energy in combination with electrical energy to the heart, usually after the onset of an arrhythmia. A vibrational transducer and suitable electrical contacts may be combined in a single housing or distributed among various housings, and will usually be implantable so that the vibrational transducer can be directed at a target portion of the heart. Alternatively, external systems comprising the vibrational transducer and electrical contacts are also described.

Abstract: The epicardial pacing system and related method includes an epicardial catheter configured to be disposed in the middle mediastinum of the thorax of a subject for use in electrical pacing of the heart at one or more locations on the epicardial surface. The epicardial pacing catheter may include at least one electrode whereby the electrode is insulated on at least one side to allow pacing of the heart without damage to adjacent anatomical structures.

Abstract: A system for pericardial lead implantation is disclosed herein. The system includes an implantation tool and a stimulation lead. The implantation tool includes a tubular body, a first lumen, a second lumen, a stylet or guidewire, a first port, and a second port. The first and second lumens longitudinally extend through tubular body. The first port is in communication with the first lumen, and the second port is in communication with the second lumen. The stylet or guidewire is longitudinally displaceable in the first lumen and across the first port. A tissue adhesive is selectively administrable through the second port via the second lumen. The stimulation lead includes a distal end and an engagement feature. Placing the engagement feature in the first port and causing the stylet or guidewire to displace in a first direction across the first port causes the lead to attach to the implantation tool.

Abstract: A medical electrical lead for conducting electrical signals between an electrical stimulator and a heart site includes a lead body extending from a distal non-conductive disk member to a proximal connector for attachment to the stimulator, first and second spaced electrodes protruding from the disk member for puncturing engagement with the epicardial surface of the heart in the region of an AVN fat pad containing ganglia which extend to the AV node providing an electrical connection between the atrium and the ventricle, a first conductor extending from the first electrode to a first terminal of the connector, and a second conductor extending from the second electrode to a second terminal of the connector such that electrical current from the electrical stimulator is caused to flow through the ganglia between the first and second electrodes to stimulate the AV node to control ventricular rate in the presence of atrial fibrillation.

Abstract: This invention relates to a myocardial pad used in cardioversion, pacing, or the like and to a myocardial lead and a therapeutic apparatus for cardiac disease comprising the same. The myocardial pad of this invention is bondable to epicardia and has conductivity, biocompatibility, and biodegradability. Using this pad, the myocardial lead can be immobilized onto the atrium without suture. Thus, bleeding from the atrium, which is a lethal complication, caused by lead removal can be prevented.

Abstract: Two through holes are formed in a first electrode part 10 to penetrate the first electrode part 10 in the extending direction of a substrate 30. The same two through holes are also formed in a second electrode part 20. A first lead 40 is inserted in and connected to one of the through holes of the first electrode part 10. A second lead 50 is inserted in the other through hole of the first electrode part 10 while it is insulated from the first electrode part 10 and engaged with an opening edge of the other through hole. An end of the second lead 50 is inserted in and connected to one of the through holes of the second electrode part 20. An interval between the first electrode part 10 and the second electrode part 20 is determined by the second lead 50.

Abstract: A method and apparatus for providing positive fixation of medical components to a portion of pericardial tissue via both vacuum- and/or mechanically-assisted means. A source of vacuum couples via a lumen to a recessed portion of a body structure deployed into the pericardial space. The recessed portion is adapted to form a seal around its periphery with adjacent pericardial tissue so that when the recessed portion is evacuated, the tissue is drawn into the recessed portion. Then, a sharpened instrument, such as a stylet, is deployed through the lumen and pierces the tissue, thus anchoring the body structure. A source of fluid may also be included for delivery to the pericardial space (e.g., contrast media; saline solution; biological, genetic and pharmaceutical substances and the like).

Abstract: Medical electrical leads are provided including fixation features for acute and chronic fixation of a portion of the respective leads within the cardiac venous system. The medical electrical lead includes an elongate body having proximal and distal regions. Tissue contacting portions are selectively located in the distal region to contact an inner surface of the cardiac vessel when the lead is in an implanted position. The tissue contacting portion(s) include fixation features adapted to frictionally engage the inner surface of the cardiac vessel and promote tissue in-growth for chronic fixation. In some embodiments, the fixation features are detachable from the lead such that the lead can be extracted from its implanted position after tissue in-growth occurs.

Abstract: The present application discloses a tissue marker that may be permanently applied to cardiac (or other) tissue by means such as, but not limited to, a minimally-invasive procedure to allow for pre- and post-op lesion site testing, with the marker also preferably being radiopaque to facilitate post-op imaging. More specifically, the marker may preferably comprise or include an electrode as part of an integrated assembly. The marker may be mounted on the tissue with a suitable tissue retention member for securing the marker in place. The disclosed examples include one or more tissue retention members, and in an exemplary embodiment comprises a pair of clips for securing the assembly to a target tissue. Each retention member or clip has a conductive lead with an electrically conductive surface in the form of a patch associated therewith.

Abstract: A single-handle cordless internal defibrillator includes a pair of paddles, and a pair of electrodes that are respectively connected to a first-end portion of the pair of paddles. The pair of paddles has a second-end portion in communication with a single-handle, with a least one paddle of the pair of paddles being pivotable about a pivot arranged between the one paddle and the single-handle. A regulator arm in communication with the pivot adjusts the pivot of at least one paddle about the pivot so that the distance between the electrodes is variable by moving the regulator arm, and defibrillator circuitry is arranged within the single-handle. A dual-handle structure also provides tangle-free and clutter-free applications as the defibrillator circuitry is self-contained in the handle/handles or paddles of the defibrillator, eliminating the need for long cables which obstruct and can contaminate an operating room.

Abstract: To provide a method of cardiac surgery which is capable of facilitating the manipulation of devices in a thoracic cavity so as to thereby simplify the surgery, as well as alleviating physical burdens on a patient, and a defibrillation electrode, a defibrillator, and an endoscope apparatus for the same. There is provided a method of cardiac surgery, comprising: using a device which comprises a treatment unit to be inserted into a thoracic cavity for performing treatment of a heart; inserting a distal end of this device between the heart and a pericardium; thereafter piercing through the pericardium with the distal end of the device; and performing treatment of the heart from the outside of the pericardium by using the treatment unit.

Abstract: One embodiment of the present invention provides a lead electrode assembly for use with an implantable cardioverter-defibrillator subcutaneously implanted outside the ribcage between the third and twelfth ribs comprising the electrode.

Abstract: A system or appliance to treat heart failure (HF) conditions. The appliance includes a structural support or cardiac constraint to limit further distension of weakened heart tissue. The appliance also includes an implantable stimulation pulse generator and controller such that the appliance can automatically monitor cardiac activity and provide therapeutic stimulations for detected arrhythmias. The appliance can also include one or more surface electrodes. The surface electrodes can be arranged on opposite sides of the heart to apply relatively spatially uniform stimulation potentials across the heart with reduced shunting around the target tissue. A surface electrode can also be arranged to wrap substantially about a periphery of the patient's heart and used with an internal electrode to apply a relatively homogeneous shock while facilitating lower voltage and smaller shocking capacitors.

Abstract: A gastro-electric stimulation system includes an INS for producing an electrical stimulation signal, at least one medical electrical lead, and at least two electrical contacts. The medical electrical lead has a proximal end and a distal end, the proximal end being connected to the INS, the distal end being adapted for placement in or near a patient's stomach or appropriate nerve or nerve portion. The electrodes are disposed near the distal end of the medical electrical lead, and are electrically connected through the medical electrical lead to the INS to receive the electrical stimulation signal and convey such signal to the selected electrode implant position. The electrical stimulation signal is provided in an amount and manner adapted to increase the pH of the gastric acid in the patient's stomach and/or to decrease the amount of gastric acid produced thereby.

Abstract: A heartwire comprises a wire having a proximal end and a distal end, at least part of the distal end being conductive so as to be usable in heart stimulation; and attached to said distal end, an end structure adapted for non-invasively maintaining the distal end in position adjacent the heart. The end structure may comprise an irregular or three-dimensional, atraumatic structure adapted for engaging a surgical material secured to the heart, for maintaining said heartwire in position relative to said surgical material. The surgical material may be a pledget, and the end structure may comprise at least one of a pigtail, a hook, a tine and a suture sized and shaped for engaging the pledget so as to maintain the heartwire in position. The heartwire may comprise a second wire having a corresponding distal end structure and may be a bipolar heartwire. An arrangement for stimulating a heart may comprise the foregoing heartwire, in combination with a surgical material for being secured to the heart.

Abstract: A system for treating the heart including a cardiac harness configured to conform generally to at least a portion of a patient's heart. The system also includes an electrode associated with the cardiac harness and positioned on or proximate to the epicardial surface of the heart. In order to ensure that the electrode will operate with a pulse generator, the system has an impedance between approximately 10 ohms and approximately 120 ohms.

Abstract: A medical system includes a first low voltage electrode adapted for intimate contact with tissue at an implant site, in order to provide pacing stimulation in conjunction with a second low voltage electrode. A porous layer is formed over the second electrode; the porous layer allows conduction therethrough while preventing contact between the second electrode and tissue in proximity to the implant site.

Abstract: Implantable cardiac monitoring and stimulation methods and devices with epicardial leads having sensor feedback. A fixed or extendable/retractable sensor may be displaceable within the lead's lumen and configured to sense the presence of an anatomical feature or physiological parameter of cardiac tissue in proximity with the lead body's distal end. The sensor may include an ultrasonic sensing element, a perfusion sensor, a photoplethysmographic sensor, or a blood oximetry sensor. Methods of determining suitability for implanting a lead involve the steps of accessing an epicardial surface of the heart, and moving the cardiac lead to an implant site at the epicardial surface. A transmitted signal is directed at the implant site. A reflected signal is received, indicative of the presence of a blood vessel at the implant site. A determination may be made to determine whether the implant site is suitable or unsuitable based on the reflected signal.

Abstract: Systems including an implantable receiver-stimulator and an external controller-transmitter system are used for leadless acute stimulation of the heart, particularly after heart surgery. Cardiac pacing and arrhythmia control is accomplished with one or more implantable receiver-stimulators and an external system that alternatively includes the use of an external pacemaker. Receiver-stimulators are implanted in the heart during surgery or during an acute interventional procedure and then a triggered for stimulation by using the external system. In one embodiment of these systems, a controller-transmitter is activated by an external pacemaker to time the delivery of acoustic energy transmission through the body to a receiver-stimulator at a target tissue location. The receiver-stimulator converts the acoustic energy to electrical energy for electrical stimulation of the heart tissue.

Abstract: A cardiac harness for treating or preventing congestive heart failure is configured to be placed about at least a portion of a patient's heart so as to apply a mild compressive force on the heart. In one embodiment, the cardiac harness comprises a plurality of spaced apart conductive panels arranged so that there is no electrical continuity circumferentially around the harness. In an additional embodiment, a cardiac harness is provided that is insulated so as not to conduct electricity circumferentially about the harness.

Abstract: A method for routine monitoring and quality assurance of field asymmetry of high energy circular radiation beam producing equipment. The quality assurance process of field symmetry for devices such as stereotactic radiosurgery (SRS) systems is simplified by directly measuring the integration of the half-beam profile. The method of the invention provides that the field symmetry is obtained by positioning the tip of an ion chamber, with a collecting length approximately half the diameter of the beam, at the central axis of the beam, and rotating the ion chamber at varying angular positions, acquiring and comparing readings at desired angular positions. Each pair of readings from positions 180 degrees opposed from each other, are plugged into the equation, Asymmetry=2(R1?R2)/(R1+R2) to compute asymmetry.

Abstract: The present invention is a myocardial lead attachment system for securing a lead within the myocardium. The attachment system includes an anchor configured to engage the heart, a tether coupled to the anchor and a lead body. The lead body has a proximal end, a distal end, a lumen for accepting the tether and a lock housing in the lumen. A lock structure is on the tether and mates with the lock housing and restrains motion of the lead with respect to the tether in either of a proximal or a distal direction.