Abstract: An implantable cardioverter defibrillator (ICD) including a set of leads having electrodes disposed therein. The electrodes may include a weld electrode connected to an internal wire of the lead and the ICD and a tip electrode. The tip electrode may have a set of grooves or cut out regions in its outer surface to provide edge effects for currents applied through the tip electrode. The grooves or cut out regions may form gaps in the surface of the tip electrode exposing a medical compound that is housed within the tip electrode. The medical compound may elute through the gaps.

Abstract: Methods facilitate inserting a cardiac lead into a patient's vasculature. A cardiac lead system includes a cardiac lead having a lumen, and a guide member displaceable within the lumen. The guide member includes a guide wire extension that extends distal to the elongated body of the guide member. The guide wire extension is dimensioned to pass through an external distal opening of the cardiac lead lumen. Engagement of stop features or a stop mechanism of the cardiac lead system provides a push point for advancing the cardiac lead system through the patient's anatomy.

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: A lead includes a lead body extending from a proximal end to a distal end and having an intermediate portion. A shocking electrode is disposed proximate the distal end of the lead body, and a pacing electrode is disposed along the intermediate portion of the lead body. The distal end of the lead body includes a preformed biased shape.

Abstract: An extendable medical lead comprises a lead body and a sheath defining a cavity that encloses a length of the lead body. The length of the lead body enclosed within the sheath may be coiled or otherwise gathered such that when extended, the length of the enclosed section of the lead body is greater than the length of the sheath. The sheath may include a seal to help prevent contaminant entry into the cavity in order to help reduce tissue in growth around the length of the lead body disposed within the sheath. A portion of the length of the lead body enclosed within the sheath exits the cavity through an aperture defined by the seal when a tensile force is applied to the lead body.

Abstract: A medical lead includes a pitted, grooved or threaded electrode array tip and a flexible tube or sheath encompassing the electrode array located near the lead tip. In some embodiments, the electrode array adheres to tissue, the tube or sheath adheres to the electrode array at the distal end of the electrode array or the tube or sheath adheres to tissue at the proximal end of the tube or sheath. Embodiments of the tube or sheath may be made from biodegradable material and can include electrode windows spaced along the tube or sheath corresponding to placement of electrode contacts of the electrode array.

Abstract: A distal section of an implantable medical electrical lead body includes a pair of pre-formed arcuate segments between which an approximately straight segment extends. The approximately straight segment includes a first portion extending distally from a first of the pair pre-formed arcuate segments, a second portion extending from the first portion, a third portion extending from the second to a second of the pair pre-formed arcuate segments. An electrode is coupled to the second portion of the approximately straight segment, and the adjacent first portion has a stiffness which is less than that of the first of the pair pre-formed arcuate segments and preferably less than the stiffness of the third portion, so that, when the distal section of the lead body is implanted, for example, within a cardiac vein, the lead buckles to bring the electrode into closer contact with surrounding tissue.

Abstract: An implantable cardioverter defibrillator (ICD) including a set of leads having electrodes disposed therein. The electrodes may include a weld electrode connected to an internal wire of the lead and the ICD and a tip electrode. The tip electrode may have a set of grooves or cut out regions in its outer surface to provide edge effects for currents applied through the tip electrode. The grooves or cut out regions may form gaps in the surface of the tip electrode exposing a medical compound that is housed within the tip electrode. The medical compound may elute through the gaps.

Abstract: Method and system of increasing safety of ablation of cardiac arrythmias, especially AVNRT and antero-septal accessory pathway ablations. A computer based system acquires, conditions, and analyzes the timing relationships between atrial and ventricualr signals during normal sinus (NSR) and junctional rhythms (JR) during ablation. If the timing analyses determines a safety issue, such as loss of retrograde conduction during junction rhythm, while slow pathway modification is being performed, the computer electronically disconnects the ablation circuit. This immediately stops the energy delivery to the tissues and provides a chance to reposition the ablation catheter tip to a more safer location. The ablation may be using radiofrequency (RF), cryoablation, or with high intensity focused ultrasound (HIFU). The functionality and circuitry of the system may also be incorporated within an ablation generator, EP recording and monitoring system, or a cardiac mapping system.

Abstract: A medical electrical lead configured to be coupled to a pulse generator in a cardiac rhythm management system. The lead comprises a proximal terminal connector configured for coupling the lead to the pulse generator, and a plurality of longitudinally arranged lead segments each configured to exhibit one or more predetermined physical characteristics based on the implantation location for the respective segment. The lead segments may be pre-fabricated as separate modules optimized for the operating environment and/or delivery requirements of the respective segments. The pre-fabricated modules are longitudinally arranged and joined to form the lead.

Abstract: A catheter particularly useful for ablation lesions within a tubular region of or near the heart is provided. The catheter comprises an elongated flexible tubular catheter body having an axis and proximal and distal ends. An ablation assembly is mounted at the distal end of the tubular body. The ablation assembly has a preformed generally circular curve having an outer surface and being generally transverse to the axis of the catheter body. The ablation assembly comprises a flexible tubing having proximal and distal ends that carries a tip electrode at its distal end. An electrode lead wire extends through the catheter body and into the ablation assembly and has a distal end connected to the tip electrode. In use, the distal end of the catheter is inserted into the heart of a patient.

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: A lead assembly includes a lead body and at least one cables at least partially disposed within the lead body. The cable has a non-electrode portion and an electrode portion, where the non-electrode portion extends within the lead body, and the electrode portion is external to the lead body.

Abstract: A mapping catheter comprises a catheter body and a mapping assembly. The catheter body has an outer wall, proximal and distal ends, and at least one lumen extending therethrough. The mapping assembly comprises a generally straight proximal region attached to the catheter body, a generally circular main region distal the proximal region having an outer circumference, and a generally straight distal region distal the main region. The mapping assembly also comprises a support member having shape-memory, a non-conductive covering over the support member, and a plurality of electrodes on the non-conductive covering along the generally circular main region.

Abstract: An improved catheter is provided that is particularly useful for mapping the electrical activity in a heart. The catheter comprises a plurality of spines each capable of obtaining electrical, mechanical and locational data. The catheter comprises an elongated catheter body having proximal and distal ends and at least one lumen extending longitudinally therethrough. Mounted at the distal end of the catheter body is a mapping assembly having at least two spines, each having a proximal end attached at the distal end of the catheter body and a free distal end. Each spine comprises at least one location sensor and at least one electrode, preferably a tip electrode and at least one ring electrode. The spines may be arranged in an expanded arrangement wherein each spine extends radially outwardly from the catheter body or in a collapsed arrangement wherein each spine is disposed generally along the longitudinal axis of the catheter body.

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: An implantable multi-conductor endocardial lead for a cardiac stimulator includes a tubular lead body of flexible resilient insulative material having a first lumen and a smaller diameter tubular member of similar material having a second lumen is coaxially received in the first lumen. An outer coil conductor is received within an annular cavity between the tubular lead body and the tubular member. An elongated inner coil conductor is received within the second lumen. A tip electrode at the distal end of the lead is coupled to the inner coil conductor and a ring electrode proximally spaced from the tip electrode is coupled to the outer coil conductor. All components except for the outer coil conductor have a normally straight configuration and the outer coil conductor is pre-shaped into a generally circular looped configuration such that, upon assembly, the resulting endocardial lead results in a J-configuration at its distal end.

Abstract: A stimulation electrode lead for connecting to an electrotherapy device such as a pacemaker, a defibrillator or the like, is disclosed. The stimulation electrode lead is configured for intraluminal placement within a blood vessel or within the heart of a patient, and comprising a proximal and a distal end, an electrode lead plug at the proximal end of the stimulation electrode lead, and the stimulation electrodes in the region of the distal end of the stimulation electrode lead, said stimulation electrodes having an electrically conductive outer surface and being connected electrically to the electrode lead plug, the stimulation electrode lead having at least one distal electrode support member in the region of its distal end, said support member supporting at least one electrode and being connected by a conductor link to a distal end of a first, extended portion of the electrode lead, wherein the conductor link is preformed so that when in the relaxed state it is not extended and can be elastically extended.

Abstract: An implantable medical lead for transmitting electrical signals between an implantable medical device and selected body tissue comprises a lead body having a distal end portion, a proximal end and an electrically insulating, elongated housing connecting the distal end portion and the proximal end. The proximal end of the lead body carries an electrical connector assembly adapted to be electrically connected to the implantable medical device and the distal end portion of the lead body carries at least one electrode electrically coupled to a terminal contact on the connector assembly. The lead comprises at least one surface susceptible during use of the lead to the accumulation of electrostatic charges, the at least one surface having a coating comprising carbon nanotubes.

Abstract: Medical device leads with magnetic shielding and methods of shielding medical device leads from magnetic fields during medical procedures such as magnetic resonance imaging (MRI) are described. An illustrative implantable medical device includes a lead including a lead conductor having a length and a helically coiled ribbon shield radially surrounding the lead conductor along at least a portion of the length of the lead. The ribbon shield can include one or more inner ribbon conductors and/or one or more outer ribbon conductors. The outer ribbon conductor can have a variable width (e.g., a necked-down configuration, an arrowhead configuration, or an undulating configuration) along the length of the lead. In some cases, the helically coiled ribbon has a variable pitch along the length of the lead that may be the same as or different from that of the lead conductor pitch.

Abstract: An implantable lead comprises a lead body extending from a lead proximal end portion to a lead distal end portion. The lead body includes one or more longitudinally extending lumens. A conductor is received in, and extends along, a lumen. In varying examples, the implantable lead further comprises a tubular electrode co-axial with, and overlying portions of, the lead body. In one example, a lumen wall is sized and shaped to urge an electrically conductive interposer coupled with the conductor toward an inner surface of the electrode. In another example, a ring member is disposed within a lumen and the conductor is drawn and coupled thereto. In yet another example, an electrically conductive connector couples a first and a second conductor via grooves or threads. In a further example, an axial support member couples a distal end electrode and the lead body. Methods associated with the foregoing are also discussed.

Abstract: The invention is directed to medical lead designs that facilitate implantation of the leads through tissue. For example, the leads can implanted though tissue for placement of distal tips of the leads in locations on the opposing side of the tissue. The leads include fixation elements, such as flexible tines, that facilitate fixation to the tissue. The fixation elements can protrude from lead at a location more than 5 millimeters from the distal-tip of the lead such that when the distal tip has passed through the tissue, the fixation elements anchor in the tissue.

Abstract: An electrode lead for implantation into a small heart vessel, especially into a coronary sinus, is provided with an elongated outer insulating lead body (1), having a proximal end (2), a distal end (3) and at least one electrode pole (4) at the distal end (3). At least one electrical conductor unit (6, 6?) leads to said electrode pole (4), each of said electrical conductor units (6, 6?) having a conductor core (7) and a separate insulating sheath (8) surrounding said conductor core (7). A lumen (9) is provided in said insulating lead body (1), being defined by a tubular envelope (10), to accommodate a guide wire means (11). The at least one electrical conductor unit (6, 6?) and the envelope (10) of the lumen (9) are each slidable relative to each other along their longitudinal direction (L) and fixed relative to each other at least in the vicinity of the distal end (3) of the lead body (1).

Abstract: A guide catheter assembly for accessing lateral branch veins of the coronary sinus includes a guide catheter and a pacing lead. The guide catheter has a central lumen therethrough, a proximal end and a distal end pre-formed with a guide curve. The pacing lead is slidably receivable within the guide catheter lumen. The pacing lead has a proximal end and a distal end formed with a first curve and a second curve extending proximally from the first curve. The second curve is adapted to mate with the guide curve to direct the first curve into a selected branch vein of the coronary sinus. The second curve may be pre-formed in the pacing lead, or may be imparted to the pacing lead via a stylet or inner catheter.

Abstract: An implantable lead for sensing mechanical activity of a human heart has an insulating polymeric tube extending from a proximal end to a distal end of the lead, an electrical conductor provided in the lumen of the polymeric tube, and a sensor connected to the conductor at the distal end thereof. The polymeric tube is provided with a conductive surface layer along the inner face between the polymeric tube and the electrical conductor, the conductive surface layer being in electrical contact with this conductor. Accumulation of electrical charges between the electric conductor and the polymeric tube is thereby prevented.

Abstract: An implantable medical lead includes a device, such as a physiological sensor, that is coupled to one or more stimulation/sensing sensing conductors within the lead. When the implantable medical lead is coupled to an implantable medical device, the device carried by the lead both receives power from, and communicates with the implantable medical device via the one or more stimulation/sensing sensing conductors. Each of the one or more stimulation/sensing sensing conductors is also coupled to an electrode that is exposed to body tissue.

Abstract: A method of accessing lateral branch veins of the coronary sinus with a pacing lead and guide catheter assembly. The guide catheter has an open lumen extending therethrough and a distal end provided with a pre-formed guide curve, while the pacing lead has a distal end provided with a first curve and a second curve extending proximally from the first curve. The guide catheter is inserted into an access vessel of the heart and advanced along the access vessel to the coronary sinus. The pacing lead is inserted into the guide catheter lumen and advanced distally through the guide catheter lumen. The pacing lead is rotated by advancing the second curve of the pacing lead through the guide curve to align the first curve with a pre-determined plane. The first curve of the pacing lead into one of the lateral branch veins of the coronary sinus.

Abstract: A catheter is provided that has a basket-shaped electrode assembly with an improved mechanism for expanding and contracting the electrode array. The expansion mechanism is designed to permit reproducible reintroduction of the catheter into the heart. The catheter comprises an elongated catheter body having at least one lumen therethrough. A basket-shaped electrode assembly is mounted at the distal end of the catheter body. The basket assembly comprises a plurality of spines connected at their proximal and distal ends, each of which comprises at least one electrode. The basket assembly has an expanded arrangement wherein the spines bow radially outwardly and a collapsed arrangement wherein the spines are arranged generally along the axis of the catheter body. An expander is attached at or near its distal end to the distal ends of the spines and extends through the catheter body. The expander has a proximal end that extends out the proximal end of the catheter body a lumen extending therethrough.

Abstract: A cardiac rhythm management device that can comprise a lead and a pulse generator. The lead can comprise lead body, a composite conductor, a stylet guide, two or more electrodes and a proximal connector. The composite conductor can comprise two or more conductors which can electrically couple the electrodes to the proximal connector. The electrodes can be disposed on a distal portion of the lead body and can be longitudinally spaced from one another. The proximal connector can be configured to couple to the pulse generator.

Abstract: A medical probe for mapping is provided. The medical probe includes an elongated member, a first mapping ring electrode mounted to the elongated member, and a second mapping ring electrode mounted to the elongated member. The first and second mapping ring electrodes are electrically insulated from each other. The second mapping ring electrode is located substantially concentric to the first mapping ring electrode, and is coaxially surrounding the first mapping ring electrode.

Abstract: An abnormally rapid ventricular cardiac rate that results from atrial fibrillation can be reduced by stimulating a vagal nerve of the heart. An apparatus for such stimulation includes a power transmitter that emits a radio frequency signal. A stimulator, implanted in a blood vessel adjacent the vagal nerve, has a pair of electrodes and an electrical circuit thereon. The electrical circuit receives the radio frequency signal and derives an electrical voltage from the energy of that signal. The electrical voltage is applied in the form of pulses to the pair of electrodes, thereby stimulating the vagal nerve. The pattern of that stimulating pulses can be varied in response to characteristics of the atrial fibrillation or the ventricular contractions.

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: A lead includes a lead body and an electrode disposed proximate a distal end of the lead body. A retaining member is disposed proximate the distal end of the lead and adapted to retain the electrode proximate an interatrial septum when the retaining member is located on a left atrial side of the interatrial septum.

Abstract: One example includes an implantable lead including an elongate lead body which includes a proximal portion and a distal portion. In the example, the lead includes a coupler configured to couple to an implantable medical device. The lead includes a first conductor, coupled to the coupler, and extending away from the coupler at least partially through the lead. The lead includes a first electrode, located on the lead away from the coupler and a first switch, located on the lead away from the coupler, the first switch configured to control conductivity between the conductor and the electrode. The lead also includes a first controller circuit, coupled to the conductor and including a first multiplexer circuit configured to multiplex over the conductor a first signal and a second signal, the first controller circuit configured to control the first switch based at least on the first signal.

Abstract: A medical electrical electrode includes an elongated conductive coil located over a lead body, and a conductive polymer material in contact with the lead body and located between individual coils of the elongated conductive coil. In certain embodiments, the conductive polymer is a polymer (e.g., silicone) implanted with a conductive filler (e.g., carbon black). In certain embodiments, the conductive polymer material is generally isodiametric with an outer diameter of the individual coils of the elongated conductive coil. A medical electrical electrode is fabricated by sliding an elongated conductive coil over a length of a lead body, dispersing a conductive polymer on the helical coil, inserting a tubing over the elongated conductive coil, distributing the polymer material between individual turns of the elongated conductive coil, heating the tubing so the tubing shrinks around the elongated conductive coil, and removing the tubing.

Abstract: Methods for medical lead fixation in coronary veins according to embodiments of the present invention include advancing a lead body into a branch vessel of a coronary vein, inserting a fixation line and expandable anchor structure through the lead body, past a distal end of the lead body, and into the branch vessel, engaging a wall of the branch vessel with the expandable anchor structure, and coupling the fixation line with the lead body. Apparatus for medical lead fixation in a coronary vein according to embodiments of the present invention include a lead body having one or more electrodes, a fixation line, an expandable anchor structure coupled to the fixation line, the fixation line and anchor structure deployable through the lead body into the branch vessel, and a means for coupling the lead body to the fixation line.

Abstract: A medical device lead is presented. The lead includes one or more jacketed conductive elements. The jacket comprises one or more covers. A first cover of expanded polytetrafluoroethylene (ePTFE) is in direct contact with the at least one conductive element. At least one conductive element and a ePTFE cover are coiled. The coiled conductive element can substantially retain its original coiled shape.

Abstract: A medical instrument system includes a controller and a guide instrument coupled to an instrument driver, the instrument driver configured to manipulate a distal end portion of the guide instrument in response to control signals generated by the controller. A force sensor is associated with the guide instrument or with a working instrument carried by the guide instrument, and generates force signals responsive to a force applied to a respective distal end portion of the guide instrument or working instrument.

Abstract: A medical device lead is presented. The lead includes one or more jacketed conductive elements. The jacket comprises one or more covers. A first cover of polytetrafluoroethylene (PTFE) is in direct contact with the at least one conductive element. At least one conductive element and a PTFE cover are coiled. The coiled conductive element can substantially retain its original coiled shape.

Abstract: A medical device lead is presented. The lead includes one or more jacketed conductive elements. The jacket comprises one or more covers. A first cover of polyether ketone (PEEK) is in direct contact with the at least one conductive element. At least one conductive element and a PEEK cover are coiled. The coiled conductive element can substantially retain its original coiled shape.

Abstract: Electrodes for tissue stimulation and sensing can comprise a support with nanostructures disposed on the support. Pairs of the electrodes can be placed in close proximity to one another. When electrical energy is supplied to the electrodes, an electrical field (and possibly an electrical current) can be established between the nanostructures on the electrodes. The nanostructures may have cells disposed thereon, for example myocardial cells, myocardial progenitor cells, neural cells and/or stem cells. In addition, the electrodes can be arranged in arrays.

Abstract: The invention provides a cardiac rhythm management system which includes a tachyarrhythmia detection and classification circuit programmed to detect and classify a tachyarrhythmia, a biologic therapy delivery device configured to deliver or regulate an expression cassette suitable for terminating or preventing atrial fibrillation (AF), and a control circuit coupled to the tachyarrhythmia detection and classification circuit and the biologic therapy delivery device. Also provided is an implantable medical device for use in a body having a cardiovascular system, which includes an implantable device body including at least a cardiovascular portion configured to be in the cardiovascular system, and an expression cassette incorporated into the cardiovascular portion of the implantable device body, the expression cassette selected to express a gene product that terminates or prevents AF. Further provided are methods which employ particular expression cassettes to prevent, inhibit or treat AF.

Abstract: An electrode line for intraluminal or intracardiac use for connection to a cardiac pacemaker, comprises an elongate, flexurally soft electrode line body having a distal end at which or in the proximity of which is arranged at least one distal electrode which is electrically connected to the electrical connecter and has an electrically conducting outside surface. The electrode line has a lumen for receiving a guide wire or the like.

Abstract: An implantable medical lead includes a device, such as a physiological sensor, that is coupled to one or more stimulation/sensing sensing conductors within the lead. When the implantable medical lead is coupled to an implantable medical device, the device carried by the lead both receives power from, and communicates with the implantable medical device via the one or more stimulation/sensing sensing conductors. Each of the one or more stimulation/sensing sensing conductors is also coupled to an electrode that is exposed to body tissue.

Abstract: A cardiac ablation device, including a catheter and an expandable ablation element incorporating one or more balloons at the distal end of the catheter, has a continuous passageway extending through it from the proximal end of the catheter to the distal side of the expandable ablation element. A probe carrying electrodes is introduced through this passageway and deploys, under the influence of its own resilience, to a structure incorporating a loop which is automatically aligned with the axis of the expandable ablation device, so that minimal manipulation is required to place the probe. The probe may have an atraumatic tip with a ball formed at the leading edge. The atraumatic tip prevents any tissue damage such as perforation of heart wall.

Abstract: A medical use electrical lead 10 includes an elongate body member 11 comprising an inner tubular member 12 defining a lumen 16 and a cover member 20 covering the inner tubular member 14. At least one electrode 22 is defined on an outer surface of the cover member 20. At least one pair of conductors 18 is arranged between the inner tubular member 14 and the cover member 20, the at least one pair of conductors 18 being in electrical communication with the at least one electrode 22 through the cover member 20. A radio opaque marker 28 circumscribes a periphery of the inner tubular member 14 and underlies the at least one electrode 22.

Abstract: Catheter device comprising a catheter (2), particularly an intravascular catheter, for insertion into an organ or vessel of the human or animal body, with a device for ablation of the adjacent organ tissue or vessel tissue using high-frequency currents in the region of the tip of the catheter, a device (3, 11, 12, 18, 19, 23, 24) being integrated for capturing images of the organ or vessel in the region of the tip of the catheter (10, 17, 22).

Abstract: Aspects of the invention include design rule mediated lead placement methods. Also disclosed are methods of using the resultant positioned leads, e.g., e.g., during evaluation of tissue motion, such as of a cardiac tissue motion, e.g., heart wall motion, via electric tomography, are provided. Also provided are devices and systems for practicing the subject methods. In certain embodiments, innovative data processing and display protocols, as well as systems that provided for the same, are provided. The subject methods, devices and systems find use in a variety of different applications, such as cardiac related applications, e.g., cardiac resynchronization therapy, and other applications.

Abstract: In one embodiment, the present invention provides a cardiac lead device including a fixation mechanism slidably attached to the lead such that when the fixation mechanism is expanded into contact with a body lumen, the lead may be moved relative to the fixation mechanism if desired. Such lead movement may be limited by complimentary structure on the lead body and the fixation mechanism that prevents the lead from moving unless sufficient force is applied to the lead.

Abstract: Systems and methods for treating cardiac tissue are disclosed. A method in accordance with one embodiment of the invention is directed to treating cardiac tissue that includes a primum, a secundum adjacent to the primum, and a patent foramen ovale (PFO). The method can include shrinking the primum at a first location spaced apart from the PFO, and at least partially sealing the PFO by applying energy at a second location at least closer to the PFO than the first location. A variety of techniques, including vacuum, mechanical, chemical, RF energy and ultrasound can be used to shrink the primum. In at least some embodiments, shrinking the primum can be performed independently of whether a PFO is also sealed, for example, if the patient receiving the treatment does not have a PFO.