Abstract: A device is provided for treating atrial fibrillation. A patch is inserted through a surgical incision into a patient and is configured to attach to the patient's heart. An elongate member is attached to the patch and is configured to detach from the patch after the incision is closed and the risk of postoperative atrial fibrillation has decreased. The device is configured to provide atrial defibrillation therapy to the heart upon detection of atrial fibrillation, which can include the application of electrical energy. The patch may be bioresorbable and may include bioresorbable glue for attachment to the heart. Detection of atrial fibrillation may be performed through internal or external sensors.

Abstract: A suction assisted ablation device having a support surface, suction elements disposed adjacent the support surface, at least one electrode and at least one suction conduit is provided. The device may further include fluid openings, which allow fluid to irrigate target tissue and aid in ablation. A method for ablating tissue using suction is also provided.

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: 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: 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: Minimally invasive deployable epicardial array devices are provided. The devices include deployable platform comprising two or more effectors, such as sensors and actuators, where the devices are configured to be deployed at an epicardial location via a minimally invasive, e.g., sub-xiphoid approach. In embodiments of the present invention, at least one area of the electrode patch is an electrical control area that comprises a series of effectors, e.g., sensors and/or electrodes. Other embodiments provide localized physical constraint and dynamic mechanical stimulation of the heart to effectuate physical and biological responses. Still other embodiments provide both of these functions. Also provided are methods of using the devices, as well as systems and kits that include the devices.

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: An implantable passive fixation lead is disclosed. The passive fixation lead comprises an elongate lead body having at least one elongate conductive element. The lead body includes a proximal end and a distal end. A support member has a first surface and a second surface. The second surface is coupled to the distal end of the lead body. A linking material is coupled to the first surface of the support member. A bioadhesive material is coupled to the linking material. A removable cover is placed over the bioadhesive material.

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 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 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: 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: 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.

Abstract: An epicardial pacing lead including a flexible, elongated lead body. The epicardial pacing lead has a proximal end and a distal end. An electrode is coupled to the lead body near the distal end. A housing is coupled to the lead body proximal to the electrode. A platform is at least partially encompassed by the housing. The platform includes at least four tines. Each tine is adapted for engagement with the epicardium and includes an upper section extending outwardly from the platform and a lower section extending distally at an angle to the upper section.

Abstract: A medical electrical lead adapted to stimulate a patient's cardiac plexus includes a flexible distal portion having a surface adapted to conform to an outer surface of an aortic region generally associated with the cardiac plexus. The distal portion can have one or more elongate members. Alternatively, the distal portion can have a generally planar portion. The distal portion is flexible such that it can be furled or otherwise compacted such that it can be delivered to a target stimulation site using a guide catheter or other delivery tool, such as a cannula.

Abstract: The invention is directed to devices for two minimally invasive therapeutic procedures, particularly for patients with congestive heart failure. One procedure involves providing a valve to form a passageway through the patient's left ventricular wall at the apex of the patient's heart and configured to advance instruments through the valved passageway to connect the valve leaflets of the patient's heart valve, e.g. the mitral valve, in a “Bow-Tie” configuration to prevent or minimize regurgitation through the valve. The second procedure is directed to a pacing lead with a housing and a pacing lead implanting device which are configured to pass through a trocar in the patient's chest and implanting the pacing lead on an exposed epicardial region of the patient's heart wall. The pacing lead has a penetrating electrode which is secured within the heart wall. One or both procedures may be performed on a patient with CHF.

Abstract: An exemplary lead and sheath assembly suitable for positioning in the human body includes a lead body, a sheath surrounding the lead body, one or more conductors embedded in the lead body and one or more conduits that allow for a flow of adhesive or an adhesive component to a site in the human body to thereby secure one or more electrodes in electrical contact at least one of the conductors. Various methods, devices, systems and/or other assemblies are also disclosed.

Abstract: A lead for implanting into the epicardium includes a pair of tissue anchors coupled to a tissue engaging member, forming an anchor mechanism. The tissue anchors include electrodes coupled to conductors extending from the tissue engaging member. The tissue anchors are movable from a low profile configuration to an implanting configuration in which the tissue anchors are angled away from the tissue engaging member. A device for implanting the lead includes one or more lumens, including a lead lumen and a vacuum lumen terminating at a distal opening in the device. Suction is applied at the distal opening through the vacuum lumen to draw an epicardial bleb. The anchor mechanism of the lead is withdrawn proximally past the bleb, causing the tissue anchors to pierce the epicardium. The device is then withdrawn proximally over the conductors.

Abstract: Electrical cardiac therapy devices including electrode lead assemblies having appendages coupled to an electrode. The appendage may take the form of a riser and a head having various characteristics. A further embodiment may include a cover and/or other features coupling the electrode to the riser. A lead may be provided for electrical coupling to the electrode. The lead may couple to the electrode exclusive of the riser and head. An implantable housing containing electrical circuitry for using the electrode to stimulate cardiac activity is also illustrated.

Abstract: Electrical cardiac therapy devices including electrode assemblies having openings for receiving an electrode insertion tool, and methods of inserting such electrode assemblies. The opening(s) are defined on the electrode assemblies to allow an insertion tool to be coupled to the electrode assembly and then used to push the electrode assembly into place.

Abstract: The lead body of a medical lead comprises a distal end portion carrying at least one electrode for placement in the pericardial sac of a human heart. The distal end portion of the lead body includes a multi-turn section having opposed ends, opposing forces applied to the ends tending to flatten the multi-turn section, the multi-turn section being thereby adapted to be retained within the pericardial sac. The turns of the multi-turn section may become progressively smaller from one end of the section to the other end of the section. The multi-turn section may have, in a relaxed state thereof, a generally conical, helical configuration. The at least one electrode may be carried adjacent to the end of the multi-turn section having the larger turns. Alternatively, the at least one electrode may be carried adjacent to the end of the multi-turn section having the smaller turns.

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: 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: The invention is directed to techniques for electrode placement around a heart. A harness having one or more attachment sites may be secured around the heart, and electrodes may be secured at the attachment sites as desired by the physician for the patient. The electrodes may be, for example, pacing and sensing electrodes, defibrillation electrodes, or any combination thereof. The harness holds the electrodes in place and also impedes the progress of ventricular dilation. The electrodes attached to the harness may be used for any of several purposes, such as cardiac resynchronization, selective defibrillation, measurement of impedance, pacing and cardioversion.

Abstract: A surgical electrode has an anchor which is constrained by a coating made from a bioabsorbable material. The anchor may have a barbed harpoon-like shape designed to enhance the retention strength of the anchor.

Abstract: One embodiment of the present invention provides a lead electrode assembly for subcutaneous implantation including an electrode; a riser coupled to the electrode; and a head coupled to the riser.

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: An electrode device for myocardial and the like comprises an electrode device body with elasticity; the electrode parts provided in a tip part of the electrode device body or a portion adjacent the tip part of the electrode device body, having a prevention part for missing the electrode parts; and the grip parts provided so as to nip the electrode device body so that it can avoid fear of infection disease and heart failure and connect the electrode device from an epimyocardium side

Abstract: An epicardial electrode (10) includes a generally parallelepiped flexible body (12). The epicardial electrode has an electrode element (22) attached to the center of a first side (14) for conveying electrical stimulation to cardiac muscle, and a lead (24) attached to the flexible body at a lead side (18). The lead has at least an insulated cathode conductor (26) electrically coupled to the electrode element. The epicardial electrode also has two pairs of prongs (31-34), electrically insulated from the electrode element, for anchoring the epicardial electrode to the heart. The tip (41-44) of each prong is dull. The flexible body has two elongate holes (51-52) on opposite sides of the flexible body sized to accept rods of a tool for flexing the epicardial electrode.

Abstract: A method of making a temporary medical electrical lead for pacing or defibrillating a heart of a patient.

Abstract: Medical electrical leads adapted to be implanted within the body, and particularly such leads having at least one distal electrode affixed at a site of a body organ, particularly the epicardium of the heart, employing a light-activated adhesive fixation, and methods and systems for accessing the site, applying the distal electrode to the site, and activating the light-activated adhesive. The lead is preferably implanted by performing a thoracoscopy of the thorax of the patient to visualize the site of the epicardium through a thoracoscope and to provide a pathway to the site of the epicardium. While viewing the site of the epicardium through the thoracoscope, the electrode head is inserted through the provided pathway to apply the plate against the site of the epicardium, and the light-activated adhesive is exposed to a predetermined bandwidth of light to adhere the plate to the epicardium.

Abstract: Cardiac stimulation apparatus 10 such as a lead having one or more electrodes 17, 19 and 21 for electrical contact with heart or other tissue. An adhesive substance is provided for adhesively attaching the electrodes in position in relation to the heart or other tissue to provide a non-traumatic fixing procedure. The electrodes 17, 19, 21 are positioned on a support 15 to which the adhesive substance is applied attached. The adhesive attachment allows the attached support 15 to be forcibly removed from the heart or other tissue without causing trauma to the heart or other tissue.

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: Medical electrical leads adapted to be implanted within the body, and particularly such leads having at least one distal electrode affixed at a site of a body organ, particularly the epicardium of the heart, employing a light-activated adhesive fixation, and methods and systems for accessing the site, applying the distal electrode to the site, and activating the light-activated adhesive. The lead is preferably implanted by performing a thoracoscopy of the thorax of the patient to visualize the site of the epicardium through a thoracoscope and to provide a pathway to the site of the epicardium. While viewing the site of the epicardium through the thoracoscope, the electrode head is inserted through the provided pathway to apply the plate against the site of the epicardium, and the light-activated adhesive is exposed to a predetermined bandwidth of light to adhere the plate to the epicardium.

Abstract: A temporary cardiac electrical stimulating lead comprises a stimulating electrode mounted in or on a biodegradable electrode mounting pad disposed at a distal end of the lead. The electrode mounting pad is capable of biodegradably dissolving over time in human body fluids and is loaded with a drug for therapeutically treating a medical condition of a patient's heart. The electrode mounting pad may be loaded with any of a variety of different drugs, such anti-arrhythmia or anti-inflammatory drugs. When the lead body is pulled away from the electrode mounting pad and removed from the patient, any portion of the electrode mounting pad remaining within the patient dissolves over time and disappears.

Abstract: A suction assisted ablation device having a support surface, suction elements disposed adjacent the support surface, at least one electrode and at least one suction conduit is provided. The device may further include fluid openings, which allow fluid to irrigate target tissue and aid in ablation. A method for ablating tissue using suction is also provided.

Abstract: An electrode device intended for medical equipment and arranged to be attached to a tissue of a body part of a patient, the electrode device including a clamping member, wherein the clamping member also includes a relatively thin metal sheet to be brought into an electrical connection with the body part, and is also configured and arranged to connect an electric conductive cable member to the clamping member for establishing an electric connection with the medical equipment, the connection being provided in such a way that the cable member is releasably connected to the clamping member, wherein the metal sheet forms a clip, which is arranged to be clamped to the body part by plastic deformation of the metal sheet without extending through the tissue and in such a way that electric signals are transferable between the medical equipment and the body part.

Abstract: A temporary pacemaker lead including a wire having an electrically conductive portion, a first connector portion on the wire, and an electrode having a second connector portion. The second connector portion is releasable engagement with the first connector portion so as to establish electrical conduction between the electrode and the electrically conductive portion of the wire. The electrode may be permanently affixed to the heart tissue and the wire may be easily released from and connected to the electrode.

Abstract: A lead having a distal end electrode assembly adapted for implantation on or about the heart or within a vein and for connection to a system for monitoring or stimulating cardiac activity. The electrode assembly includes conductive fixation features, such as conductive tines or flexible members, in combination with non-conductive fixation features. The conductive fixation features also include tines coated with a conductive material. The fixation features further include conductive tines which are retractable. A defibrillation coil is optionally disposed at the distal end of the lead in combination with the conductive tines.

Abstract: An electrode terminal is described for delivering a stimulation pulse to the heart or other tissues containing a linear array of fibers. The electrode terminal is elongated and adapted for orientation in a direction parallel to the tissue fibers. The device of the present invention further includes a power source for electrically energizing the terminal such that the energization of the terminal reduces the nonuniformity of the transmembrane voltage change in the tissue proximate the electrode which is produced during the stimulation pulse. Nonuniform transmembrane voltage changes are associated with arrhythmic conditions. The linear electrode of the present invention can be used for cardiac pacing, defibrillation, and the termination of tachycardia.

Abstract: The present invention provides for a sutureless clip for use in temporarily pacing the human heart. The clip comprises a generally V-shaped clip having on at least one outer surface thereof with one or more channels for the attachment of pacing electrodes, the inner surfaces of the clip optimally being textured to provide a greater contact surface area. The clip is readily deformable to allow for its attachment to the outer surface of the heart.

Abstract: A method of rolling a defibrillator electrode inserts one side of a defibrillator electrode within a recess of a first handle, the recess located at one end of the first handle, inserts an opposite side of the defibrillator electrode within a recess of a second handle, the recess located at one end of the second handle, wherein the first and second handles are then rotated toward each other about their respective axes. An apparatus for rolling a defibrillator electrode includes a first handle having a recess at one of its ends operative to slidably grasp one side of a defibrillator electrode, and a second handle, the second handle having a recess at one of its ends operative to slidably grasp an opposite side of the defibrillator electrode.

Abstract: An epicardial lead having an electrode extending from the bottom thereof in combination with an anchoring system adapted to secure the lead to the heart without the use of complex procedures or tools. In particular the lead achieves stable fixation through the provision of a flexible member moveable between a first position and a second position and a pair of fixation members connected to said flexible member, each fixation member having a distal end and a root, each flexible member connected to the electrode mounting at a point beyond the tip portion of the fixation member.

Abstract: An epicardial lead having an stab-in electrode extending from the bottom thereof in combination with an anchoring system adapted to secure the lead to the heart without the use of complex procedures or tools. In particular the lead achieves stable fixation through the provision of a flexible member moveable between a first position and a second position and a pair of fixation members connected to said flexible member, each fixation member having a distal end and a root, said distal end and root defining a plane said through which said stab-in electrode crosses.

Abstract: A myocardial lead having a tissue stimulating electrode attached via an insulated conductor to an epicardial pad the electrode embedded in the myocardial tissue of either the ventricles or the atria, for use as a pacing and/or sensing electrode. The myocardial electrode is configured to be pulled into position with a suture needle and thread. The myocardial electrode of the lead is designed to be highly reliable, to reduce exit block and fibrotic tissue growth, and to be utilized for extended periods even though designed to be implanted within the relatively thin myocardial muscle of a pediatric patient.

Abstract: An epicardial lead having an electrode extending from the bottom thereof in combination with an anchoring system adapted to secure the lead to the heart without the use of complex procedures or tools. In a preferred embodiment the epicardial lead comprises an electrode body having two oppositely disposed arms, each arm fixed for rotation, each arm having an arcuate anchor mounted to the bottom surface, each arcuate anchor having as the center of the arcuate shape the axis of rotation of the respective arm. Rotating the arms causes each arcuate anchor to move in a circular fashion such that when each arm is moved from an open position to a closed position the respective anchor is moved to engage and move through the cardiac tissue and thereby secure the lead to the heart.

Abstract: A tool and method for inserting cardiac defibrillation electrodes into a patient. The tool includes an elongated electrode support tube having a rounded distal end and a proximal end; a finger grip circumferentially connected about the electrode support tube toward the proximal end thereof; and an actuating rod slidably disposed coextensively within the electrode support tube and extending beyond the rounded distal end and the proximal end of the electrode support tube. A blunt conically shaped distal tip is connected to the distal end of the actuating rod, the distal tip having a base with a diameter larger than the diameter of the electrode support tube, and an inner surface for engaging the rounded distal end of the electrode support tube. A palm member is connected to the proximal end of the actuating rod to facilitate hand manipulation of the tool.

Abstract: An epicardial defibrillation electrode device having small conductive dirks extending therefrom to lodge into the myocardium to lower the electrode impedence. The electrode device utilizes a flexible, translucent support member to aid in the positioning of the dirks during electrode implantation. Switchable dirks extending from separate conductive members mounted to the support member are provided for pacing, sensing and defibrillation.

Abstract: Endocardial mapping and/or ablation system for introduction into a chamber of the heart formed by a wall by passage through a lumen leading to the chamber in the heart having blood therein comprising a catheter probe with proximal and distal extremities and having an elongate tubular member with at least one lumen extending therethrough extending the length thereof and with a distal extremity. A plurality of longitudinally and radially spaced apart electrodes are provided. An expandable device is secured to the distal extremity of the flexible elongate tubular member and is movable between a contracted position and an expanded position. The electrodes are mounted on the expandable device whereby when the expandable device is moved to the expanded position in a chamber of the heart the electrodes are moved into engagement with the wall forming the chamber of the heart in which the expandable device is disposed.