Abstract: A cardiac pacing lead and a method of its use. The lead has an elongated insulative lead body having a distal section formed into a curved configuration appropriate for use in a coronary sinus/cardiac vein of a patient's heart. An active fixation device is located proximal to the distal, curved section of the lead body, which carries an electrode, located along the distal portion of the lead body, spaced from the active fixation device a distance appropriate to locate the electrode adjacent the left atrium or left ventricle of a human heart when the fixation device is located adjacent the ostium of the coronary sinus. The lead is used by advancing the distal portion of the lead through the coronary ostium of the patient's heart and into the coronary sinus/cardiac vein and therefter employing the active fixation device to affix the lead to the patients heart outside of the coronary sinus/cardiac vein.

Abstract: An implantable electrical lead having an elongated insulative lead body with a longitudinal lumen therein extending from the proximal end of the lead body to a distal portion of the lead body and having an elongated stranded electrical conductor located in the lumen, the conductor having a distal end which exits the lumen at the distal portion of the lead body and which is curved to form a loop exterior to the distal portion of the lead body and which then re-enters the lead body. In some embodiments, the strands of the conductor are twisted helically in a first direction and the conductor is twisted in a second, opposite direction in that portion of the conductor located exterior to the lead body to separate strands of the conductor. The stranded conductor may exit the lumen at the distal end of the lead body or at one or more locations proximal to the distal end of the lead body.

Abstract: An anchoring sleeve for retaining an electrical lead including a sleeve base and a locking member latchable to the sleeve base to lock the locking member to the sleeve base encircling the lead and engaging it around its full circumference. The locking member may be an arcuate member joined to said sleeve base by a hinge and pivotable to latch said locking member to the sleeve base. Alternatively the locking member may be a member formed separately from the sleeve base. The base may be provided with one or more C-shaped members to temporarily retain the lead prior to latching.

Abstract: A catheter ablation system including a catheter having a distal segment carrying at least one electrode extending along the segment and having a number of temperature sensors arranged along the distal segment adjacent the electrode, each providing an output indicative of temperature. The catheter is coupled to a power source which provides R-F energy to the electrode and with temperature processing circuitry coupled to the temperature sensors and the power source which controls power output from the power source as a function of the outputs of the temperature sensors. In a preferred embodiment, the temperature processing circuitry includes circuitry for comparing the temperature indicated by the temperature sensors to a known reference sensor and circuitry for disabling subsequent use of an output of one of the sensors if the output from the sensor differs from the referenced temperature by more than a defined value.

Abstract: A method of producing a lead which is isodiametric or nearly so over the region in which an elongated coiled electrode is located and which can optionally be manufactured starting from a single extruded tubular lead body of constant diameter and the lead so produced. Rather than molding the electrode into the surface of the lead or machining the electrode so that it is flush with the surface of the lead, the present invention instead employs an extruded, multiple lumen lead body of circular cross-section which has material cut away or otherwise removed in one or more regions spaced from one another around the lead body and extending longitudinally along the region of the lead body where the coil electrode is to be located or a lead body which is so molded. The areas in which material is removed or is absent are preferably located in regions where the lead body wall is thickest, for example between adjacent lumens.

Abstract: In an implantable pacemaker.backslash.cardioverter.backslash.defibrillator, a system for correlating the delivery of an atrial cardioversion therapy to an optimum blood pressure to effect delivery of the therapy when the volume of the atrium is minimized. In a first embodiment, the blood pressure in the atrium or ventricle is monitored and delivery is timed to a low blood pressure occurring as blood is emptying from the atrium. In a variation ventricular pacing may be provided to ensure that the ventricles are contracting forcefully and at a rate which optimizes atrial emptying. In a second embodiment, the delivery of the cardioversion therapy is also timed to an optimum point or phase of the respiratory cycle. The optimum point or phase of the respiration cycle depends in part on the chamber to be cardioverted and the location of the cardioversion electrodes with respect to the chamber.

Abstract: An implantable medical lead provided with a coiled conductor extending from a connector assembly at a proximal end of the lead to an electrode on the lead body and a stranded conductor extending from the connector assembly to a point distal thereto. The stranded conductor is coupled to the coiled conductor at both of its ends and provides both for an increased resistance to fracture of the coiled conductor and a redundant conductor in case the coiled conductor does fracture.

Abstract: A medical electrical lead and a reinforced silicone elastomer used therein. The silicone elastomer used therein is preferably made from a novel silica reinforced polysiloxane material, which after vulcanization by cross-linking exhibits improved mechanical properties. The medical electrical lead features a an electrode at a distal end thereof, a connector at a proximal end thereof and an elongated electrical conductor extending between the electrode and the connector, the conductor in electrical contact with the electrode at a distal end and in electrical contact with the connector at a proximal end, the conductor comprised of a plurality of wires or wire bundles wound in a multifilar coil configuration.

Abstract: An implantable prosthetic heart valve with a suturing ring having an impermeable or semi-impermeable coating over at least a portion of the surface thereof to prevent tissue ingrowth in the coated area or areas. The suturing ring is formed of a biocompatible fabric tube of a mesh weave having interstices permeable to tissue ingrowth and first and second axial ends fastened into a torus shaped, suturing ring body having an interior directed minor surface adapted to be fitted against the exterior annular wall of a valve body and an outward directed major surface. An upper ring shaped surface is formed adjacent the upper edge of the valve body and a lower ring shaped surface adjacent the lower edge of the valve body. The intermediate band is intended to be sutured into contact with the heart tissue orifice. First and second impermeable layer of biocompatible material fill the interstices of the mesh weave in the upper and lower ring shaped surface area.

Abstract: A medical electrical lead and a reinforced silicone elastomer used therein. The silicone elastomer used therein is preferably made from a novel silica reinforced polysiloxane material, which after vulcanization by cross-linking exhibits improved mechanical properties. The medical electrical lead features a an electrode at a distal end thereof, a connector at a proximal end thereof and an elongated electrical conductor extending between the electrode and the connector, the conductor in electrical contact with the electrode at a distal end and in electrical contact with the connector at a proximal end, the conductor comprised of a plurality of wires or wire bundles wound in a multifilar coil configuration.

Abstract: A medical electrical lead having an electrode head with an internal lumen mounted to a proximal portion of the lead body and a rotatable fixation helix advanceable from the internal lumen. The helix is mounted to a rotatable shaft which is provided with a central shaft portion and circumferential shoulders proximal and distal to the central shaft portion. A seal is mounted in the lumen of the electrode head, encircling the shaft and C-shaped seal retainers are mounted in the lumen of the electrode head member proximal and distal to the seal.

Abstract: A method of fabricating a radiopaque dissolvable covering for a member on an implantable lead, including the steps of mixing a radiopaque material with a solvent to form a paste, applying the paste to the member and allowing the paste to harden. The lead preferably is provided with a drug incorporated therein which is subject to degradation at high temperature, located adjacent to the member, and the applying step preferably takes place at about room temperature. The member to which the paste is applied may be an active fixation device such as a barb or a helix or may be a deployable member such as a tine or an electrode bearing member.

Abstract: An improved lead body for implantable leads comprising a longitudinally extending core section provided with longitudinally extending grooves in which conductors are located and an outer tubular member, encasing the core and conductors.

Abstract: An implantable anti-arrhythmia device such as a defibrillator or anti-tachycardia pacemaker with an associated patient activator. The arrhythmia detection function is divided between the patient and the implanted device, rather than merely providing patient activation or a patient override. The implantable device is provided with a tachyarrhythmia recognition mechanism, which operates essentially continuously, and which, upon meeting a first set of criteria, will trigger delivery of an anti-arrhythmia therapy such as pacing, cardioversion or defibrillation. The patient is provided with an activator which informs the implanted device that the patient believes that anti-arrhythmia therapy is necessary. In response to receipt of the activation signal, the implanted device defines a time interval thereafter during which a second, less stringent set of arrhythmia detection criteria must be met, in response to which the device will deliver a cardioversion or defibrillation pulse.

Abstract: An atrial and ventricular pacemaker including an atrial pulse generator having the capability of delivering high rate atrial pacing pulses for electrophysiologic study and having the capability of delivering ventricular pacing pulses as a backup, during delivery of high rate atrial pacing pulses. Delivery of backup ventricular pacing pulses may be preconditioned upon the occurrence of a desired number, proportion or pattern of occurrences of paced ventricular beats preceding delivery of high rate atrial pacing pulses. Timing of ventricular backup pulses is synchronized to delivered atrial pacing pulses which occur closely timed to expiration of a defined ventricular escape interval for backup pacing. The defined escape interval for ventricular backup pacing may be set as a function of the average interval separating ventricular events preceding initiation of high rate atrial pacing.

Abstract: An implantable electrical lead having a lead body with a longitudinal lumen therein and a stranded electrical conductor located in the lumen and which exits the lumen at a distal portion of the lead body, the distal end of the conductor being curved to form a loop and reentering the lumen, terminating within the lumen alongside a more proximal portion of the conductor. The portion of the conductor exterior to the lumen is wound around the lead body to form a coiled electrode. In some embodiments the distal end of the conductor is coupled to a more proximal portion of the conductor to form a loop and the loop is wound around the lead body to form a bifilar coil. In other embodiments the conductor is wound around the lead body to form a mono-filar coil. The distal end of the conductor is mechanically and electrically coupled to a more proximal portion of the conductor, within the lumen.

Abstract: A medical device for insertion into human body having an echogenic portion of enhanced visibility in an ultrasound scan. The echogenic portion includes an echogenic material comprising a plastic impregnated with sonically reflective particles, the particles having an average size of less than 500 nanometers and formed of a substance having a specific gravity of 5 or greater. Preferably the particles have an average size of less than 100 nanometers and the sonically reflective particles are 5% to 40% of the echogenic material.

Abstract: A cardiac pacing lead for pacing the atria and a method of its use. The lead is provided with a mechanism for maintaining an atrial pacing electrode adjacent stimulable tissue in a patient's superior vena cava and an additional electrode locatable in the right ventricle or elsewhere when the atrial electrode is so located. One such mechanism for maintaing the atrial electrode's position may be a lead body displaying pre-formed laterally extending curves sized to span a patient's superior vena cava, with the atrial electrode located thereon.

Abstract: An implantable electrical lead having an elongated lead body carrying a conductor therein and an elongated electrode extending from the lead body and coupled to the conductor. The lead is provided with an insulative tubular sheath mounted around the electrode and slideable thereon, the sheath having a length less than that of the electrode. Optionally, the sheath is provided with a mechanism for facilitating its removal from the electrode, which may take the form of a weakened zone formed in the sheath. The lead may be provided with a plurality of insulative sheaths slidably mounted around the electrode, and each sheath is preferably provided with a mechanism for stabilizing the location of the sheath along the electrode, which mechanism may function to frictionally engage the sheath with the electrode or to compress the sheath around the electrode.

Abstract: A method and apparatus for ablation of body tissue. A catheter provided with a hollow needle is employed both for mapping the location to be ablated by injection of an excitability reducing agent and for ablating tissue, employing RF energy in conjunction with an injected, conductive fluid.