Abstract: A device for percutaneous insertion into a fluid passageway of a human body, such as an artery is provided with one or more thermocouples disposed on a flexible, resilient wire lead and coupled to a temperature monitor. The wire lead includes a distal portion formed in a single, oval, looped shape or a double, ovoid or basket-like, looped shape with the thermocouples disposed on a side or tip of the shape. The wire lead is configured, e.g., by insertion in a guidewire, for slidable movement through the artery to an area of interest, e.g., at a buildup of arteriosclerotic plaque, on an inner surface of the artery, to bring the thermocouple into resiliently biased contact with the inner surface at the area of interest for measurement of the temperature there.

Abstract: A catheter for indirect left atrial mapping from the left pulmonary artery is disclosed. The catheter includes an elongated flexible member with a distal end and a proximal end. Located at the distal end is a balloon and an array of mapping electrodes. Located at the proximal end is a manifold to which various ports are secured. In a second embodiment, the catheter differs from the first embodiment in that interspersed within the array of mapping electrodes are defibrillation electrodes. Also, located proximally of the array of mapping electrodes is an array of defibrillation electrodes. In a third embodiment, the catheter differs from the first embodiment in that five defibrillation electrodes are located between the array of mapping electrodes and the balloon. Located proximally of the array of mapping electrodes is an array of defibrillation electrodes.

Abstract: A probe that may be used to create circumferential lesions in body tissue and, in some implementations, may also be used to perform mapping functions. The probe includes a collapsible/expandable structure that supports electrodes or other operative elements against the body tissue.

Abstract: The invention relates to a method for permeabilization of a cell structure consisting of a single cell, an intracellular structure or an organelle comprising the following steps: (a) microelectrodes, preferably two carbon fibre electrodes or hollow fibre electrodes, are provided, (b) the microelectrodes are connected to a power supply, (c) the electrodes, individually controlled by high-graduation micromanipulators, are placed close to the cell structure at an appropriate inter-electrode distance, and (d) a highly focused electric field of a strength sufficient to obtain electroporation is applied between the electrodes. The method may be used in order to transfer cell impermeant solutes, such as drugs or genes, into the cell structure or out of the cell structure, in biosensors, in the treatment of tumours and neurodegenerative diseases and in the study of biophysical processes.

Abstract: An improved system and method for placing implantable medical devices (IMDs) such as leads within the coronary sinus and branch veins is disclosed. In one embodiment, a slittable delivery sheath and a method of using the sheath are provided. The sheath includes a slittable hub, and a substantially straight body defining an inner lumen. The body comprises a shaft section and a distal section that is distal to, and softer than, the shaft section. A slittable braid extends adjacent to at least a portion of one of the shaft section and the distal section. In one embodiment of the invention, the sheath further includes a transition section that is distal to the shaft section, and proximal to the distal section. The transition section is softer than the shaft section, but stiffer than the distal section.

Abstract: A bidirectional mapping catheter is provided. The catheter comprises an elongated flexible tubular catheter body having an axis and proximal and distal ends. A mapping assembly, which is mounted at the distal end of the tubular body, has a preformed generally circular main region having an outer surface that is generally transverse to the axis of the catheter body. The generally circular main region has proximal and distal ends and carries a plurality of spaced apart electrodes. An electrode lead wire is associated with each electrode. Each electrode lead wire has proximal and distal ends and extends through the catheter body and into the mapping assembly. The distal end of each electrode lead wire is electrically connected to its associated electrode. First and second puller wires are provided. Each puller wire has proximal and distal ends and extends through the tubular catheter body. The distal end of each puller wire is anchored at or near the distal end of the catheter body.

Abstract: A device for the mapping of cardiac arrhythmia foci including a catheter body having a distal tip, first and second point electrodes, which are secured to the catheter body and which form a first bipolar pair of electrodes, and third and fourth point electrodes, which are secured to the catheter body and which form a second bipolar pair of electrodes, wherein a line passing between the third and fourth point electrodes is within about 45 degrees of being perpendicular to a line passing through the first and second point electrodes.

Abstract: A steerable catheter for insertion into the ostium of the coronary sinus in the right atria including a flexible catheter body, and a steerable catheter handle wherein the catheter body includes a generally straight proximal section, a deflectable distal section and a precurved tip portion located at a distal end of the deflectable distal section. Preferably, the precurved tip portion curves outside of a plane formed by the deflectable distal section from about 20 degrees to about 50 degrees.

Abstract: A method and device for the pharmacological cardioversion of fibrillation or atrial flutter is disclosed. The device is implantable in the human body and provides equipment for drug infusion using an electrocatheter positioned in the right atrium, the right ventricle, or the coronary sinus. The electrocatheter is provided with sensors which monitor the electromechanical activity of the heart and which intervene to activate the infusion in the presence of fibrillation or flutter. The catheter may be provided with at least one balloon which can be inflated and deflated to create a chamber which permits perfusion of the drug directly into the vein of Marshall.

Abstract: A system for providing medical electrical stimulation includes a pulse generator coupled to a lead having two electrodes for placement in the right atrium or for placement of one in the right atrium and one in the coronary sinus or coronary vein. In the preferred embodiment the surface area of the first electrode is smaller than that of the second electrode so that the sensed signal from the first electrode is less than that from the second. The system provides dual site pacing with essentially single site sensing without the use of extra switches, connectors, or adaptors.

Abstract: A guide wire, for measuring a physiological variable inside a living body, having few conductors is provided. The guide wire is provided with a sensor (14) for monitoring the physical variable and for forming an output signal characteristic for the value of the physical variable. The sensor is connected to a first electrical potential of an electronic unit (22) via an electrical wire (11) extending along the guide wire. An internal body electrode (17) is connected to the sensor (14) and is in contact with body fluids surrounding the sensor circuit. The guide wire (10) is inserted into a vessel of the body (25), and a second electrode (21) is applied near the internal body electrode, and the sensor circuit is powered by a second potential of the electronic unit (22) via a part of the body.

Abstract: A first electrode is positioned within an artery proximate an implanted intravascular stent. A second electrode is positioned at a separate location relative the position of the first electrode. Electrical energy is then delivered between the first and the second electrodes to produce an electrical field adjacent the implanted intravascular stent. When a intravascular stent is implanted in a coronary artery, the delivery of the electrical energy is coordinated to cardiac cycles detected in sensed cardiac signals, where the delivery of the electrical energy between the first electrode and the second electrode occurs during a predetermined portion of the cardiac cycle.

Abstract: Disclosed is a medical device for introduction into a patient's body, in particular into the patient's blood vessel, for measuring a physiological parameter. The medical device comprises means for coding the site of an application of the medical device in the patient's body and/or means for coding the effect of the site of an application of the medical device in the patient's body on the measurement of the physiological parameter.

Abstract: An ablative catheter assembly whose electrode is completely covered by a buffer layer. The buffer layer prevents areas of high current density at the surface of the catheter tip, which helps to reduce popping and clotting. The buffer layer may be in the form of a conductive fluid (such as saline solution) pumped into a cavity surrounding the electrode. In this case, the conductive fluid couples the electrode to the surrounding tissue so that RF energy will pass from the electrode to the tissue, thereby effecting ablation. Also, the buffer layer may be in the form of a porous coating which covers an electrode tip. In this case, blood or fluid which infuses the porous coating couples the electrode tip to the surrounding tissues to be ablated.

Abstract: Endocardial implantable cardiac leads are disclosed for applying electrical stimulation to and/or sensing electrical activity of the heart at one or more distal electrode positioned at a cardiac implantation site within a cardiac vessel adjacent to and at a desired orientation to the left ventricle or atrium of the heart. The distal electrode(s) is supported by a tubular electrode support having a diameter large enough to bear against the blood vessel wall and a support lumen that allows blood to flow through it. A retention stent extends proximally from a distal stent end fixed to the tubular electrode support to a proximal stent end. After advancement to the cardiac implantation site employing a lead delivery mechanism, the retention stent is expandable from a collapsed stent state in which the outer diameter of the retention stent is less than the inner diameter of the vessel to an expanded stent state.

Abstract: A sensor designed to determine the amount and concentration of analyte in a sample having a volume of less than about 1 .mu.L. The sensor has a working electrode coated with a non-leachable redox mediator. The redox mediator acts as an electron transfer agent between the analyte and the electrode. In addition, a second electron transfer agent, such as an enzyme, can be added to facilitate the electrooxidation or electroreduction of the analyte. The redox mediator is typically a redox compound bound to a polymer. The preferred redox mediators are air-oxidizable.The amount of analyte can be determined by coulometry. One particular coulometric technique includes the measurement of the current between the working electrode and a counter or reference electrode at two or more times. The charge passed by this current to or from the analyte is correlated with the amount of analyte in the sample.

Abstract: A system for detecting electrical activity within a patient's heart comprising an elongated intravascular device, such as a catheter or guidewire, having at least one bipolar electrode pair on a distal section of the elongated device to intravascularly detect electrical activity within the patient's heart. The catheter or guidewire preferably has a tubular shaft formed of braided strands which include a plurality of insulated conductors which are electrically connected to the bipolar electrodes.

Abstract: A recording and ablation catheter method and system for creating linear lesions in an atrial or other chamber of a heart is disclosed which includes an array of readily controlled electroded arcuate distal working catheter shapes that are easily deployed to contact the inner wall surface of the right atrial cardiac chamber in a manner that enables easy recording and mapping of impulses and thereafter facilitates sustained contact so that linear lesions can be produced from an array of mapping and ablation electrode devices serially spaced along the working catheter shape.

Abstract: Expandable electrodes for intravascular leads permit the electrodes to be placed and retained in the vasculature of the left side of the heart. Such electrodes can be in the form of a balloon, an expandable wire coil, or other expandable shapes.

Abstract: A pacing lead for a cardiac stimulator that includes an elongated flexible insulating lead body. An electrode is attached to the lead body at its distal end. An elongated conductor extends through a lumen of the elongated lead body for connecting the electrode to the terminal pin. The conductor is in the form of a coiled wire until it reaches approximate the electrode. It is then crimped to a cable conductor which in turn is crimped or welded to the electrode. The electrode is supported at the distal end by a molded support body which includes a lumen for a guide wire.

Abstract: An endoluminal device slippage sensor system including an electrically conductive endoluminal device and a catheter assembly to which the device is coupled for deployment into a lumen. First, second and third electrodes are associated with the catheter assembly, each respectively in direct electrical contact with a proximal, a middle and a distal portion of the device. A potential source generates a potential between the first and second electrodes and between the second and third electrodes. The potential between the electrodes is varied in accordance with a change of position of the device along the axis of the catheter assembly during deployment in which the proximal or distal portion of the device is disconnected from the first or third electrode, respectively.

Abstract: A method and system for detecting electrical activity within a patient's heart, particularly the electrical activity which causes arrhythmia, which includes a first intravascular device such as a catheter or guidewire having a plurality of sensing electrodes on a distal portion thereof which is disposed within one location of the patient's coronary vasculature and a second intravascular device such as a catheter or guidewire having a plurality of sensing electrodes on a distal portion thereof which is disposed within a second location of the patient's coronary vasculature to facilitate mapping the electrical activity of the patient's heart. Once the electrical activity has been mapped, therapeutic procedures can be initiated.

Abstract: A catheter for ablating and/or mapping tissue on the inner wall of a blood vessel, including a body portion and a tip portion having a proximal section and a distal section, the proximal section including a proximal ablation electrode and a proximal mapping electrode and the distal section including a distal ablation electrode and a distal mapping electrode, wherein the tip portion is deflectable from a first, generally straight, configuration in which the proximal and distal sections are substantially co-linear to a second, J-shaped, configuration in which the proximal and distal sections are generally parallel with a separation therebetween substantially corresponding to the inside diameter of the blood vessel.

Abstract: The invention involves a catheter for introducing a delivery member such as a guidewire having an implant coupled thereto via an electrolytically disintegratable link that is coupled to the anode of a power supply having an anode and a cathode. The catheter comprises an elongated tubular member having an outer surface, proximal and distal end portions, a lumen extending between those portions, an electrode and a conductor. The electrode is disposed within the outer surface of the tubular member in the vicinity of the distal end portion and has a surface that faces and communicates with the lumen. The electrode is electrically coupled to the conductor which, in turn, is adapted for coupling to the power supply cathode such that when the electrolytically disintegratable link is placed in an ionic solution, such as can be found in an aneurysm, and positive current is provided from the power supply to the link, current from the link may return to the cathode of the power supply via the electrode.

Abstract: A guiding catheter for delivery of intravascular devices to a patient's coronary sinus. The guiding catheter has a relatively stiff proximal section and a relatively flexible distal section, the latter being about 1 to about 6 inches in length and being configured to subselect a branch cardiac vein leading to the coronary sinus. The distal shaft section preferably has a proximal portion which has a flexibility greater than that of the proximal shaft section, and a distal portion which has a flexibility greater than that of the proximal portion of the distal shaft section, and at least one of the distal portion and the proximal portion being shaped with a bend to facilitate entry within the patient's coronary sinus. An inflatable balloon may be disposed on the distal shaft section. The guiding catheter is particularly suitable for delivering an intravascular device for sensing electrical activity into a cardiac vein to detect such activity from within the blood vessel.

Abstract: A transvenous lead specifically designed for coronary sinus implantation. The lead features a fixation ring positioned adjacent to the electrode. The ring is constructed so as to be readily pliable and bent. The ring functions to wedge or fix the lead within the coronary sinus in such a manner that the electrode is pushed against the vessel wall while the flow of blood through the vessel is not impeded. In alternative embodiments the electrode is positioned on the ring itself. In further alternative embodiments the distal portion of the lead features a pre bent nose to assist in the positioning of the lead into the coronary sinus. The nose may be oriented relative to the ring in any acceptable manner to permit the ring and the electrode to be properly positioned relative to anywhere along the coronary sinus wall.

Abstract: An over-the-wire electrophysiology catheter which has an emitting electrode on the distal tip electrically connected to a source of high frequency electrical energy. The intravascular device is configured to be advanced through a patient's cardiac veins or coronary arteries and preferably is also provided with sensing electrodes for detecting electrical activity of the patient's heart from within a blood vessel of the heart. The device forms large lesions in tissue adjacent to the blood vessel in which the device is located without significantly damaging the blood vessel to effectively terminate signals causing arrhythmia.

Abstract: A catheter for insertion in the ostium of the coronary sinus in the right atrium comprised of a main reinforced portion, an intermediate zone portion and a soft tip portion wherein a portion of the catheter is curved in a double curve, wherein the first curve is a first longitudinal curve, wherein the second curve is a second longitudinal curve, wherein the second longitudinal curve is curved in approximately the same direction as the first longitudinal curve and wherein the first and second longitudinal curves are generally coplanar.

Abstract: A conformable catheter comprising a catheter handle, an elongated catheter tube, and a distal tip portion of the catheter tube, capable of assuming a desired pre-programmed shape. A wire member is disposed within the core of the catheter's tip portion and is formed of a material, such as, for example, a shape-memory binary nickel-titanium alloy, that will assume a pre-programmed shape after pre-shaping, heat treatment, cooling and subsequent heating. To pre-program the shape of the wire member, prior to assembly of the catheter, the wire member is wound around a shaped, heat resistant fixture, heated until the temperature of the wire member exceeds the temperature at which the shape of the wire member on the fixture becomes programmed into the wire member, and cooled.

Abstract: A catheter for insertion in the ostium of the coronary sinus in the right atrium comprised of a main reinforced portion, an intermediate zone portion and a soft tip portion wherein a portion of the catheter is curved in a double curve, wherein the first curve is a first longitudinal curve, wherein the second curve is a second longitudinal curve, wherein the second longitudinal curve is curved in approximately the same direction as the first longitudinal curve and wherein the first and second longitudinal curves are generally coplanar.

Abstract: A system for detecting electrical activity within a patient's heart comprising an elongated intravascular device, such as a catheter or guidewire, having at least one bipolar electrode pair on a distal section of the elongated device to intravascularly detect electrical activity within the patient's heart. The catheter or guidewire preferably has a tubular shaft formed of braided strands which include a plurality of insulated conductors which are electrically connected to the bipolar electrodes.

Abstract: A method and system for treating a patient's heart exhibiting arrhythmia by first detecting electrical activity within the patient's heart to determine the location of the arrhythmogenic site or conductive pathway causing the arrhythmia and then creating an infarct within the region of the patient's heart where the arrhythmogenic site or the conductive pathway causing the arrhythmia is located by delivering an occluding element to a coronary artery which delivers oxygenated blood to said region of the patient's heart. In one presently preferred embodiment the occluding element is a flaccid or limp coil which when disposed in a coronary arterial passageway forms a randomly shaped, intertwined mass which quickly forms thrombus within the coronary artery to block the passage of oxygenated blood therethrough. The flaccid coil may be delivered through an inner lumen of a catheter which has a distal portion extending within the coronary artery.

Abstract: A system for detecting electrical activity within a patient's heart comprising an elongated intravascular device, such as a catheter or guidewire, having a plurality of sensing electrodes on a distal section of the elongated device to detect electrical activity from within a blood vessel of the patient's heart. The intravascular device has a first compact array with a relatively small interelectrode spacing, such as less than 2 mm, and may have a second electrode array with an interelectrode spacing much greater than the interelectrode spacing in the first array. The second electrode array may used to detect the general region of the arrhythmogenic tissue and the first electrode array is used to provide a high resolution of the electrical detection to more accurately pinpoint the location of the arrhythmogenic site. When the general region of the arrhythmogenic focus in known an intravascular device having a single array of electrodes with an interelectrode spacing of less than 2 mm may be used.

Abstract: Various endocardial lead assemblies are disclosed that may be particularly useful for placement within the coronary sinus. The lead assemblies may have open ends or closed ends. Lead assemblies having closed ends may be implanted using conventional implantation procedures. Lead assemblies have open ends may be implanted by first locating a stylet within the patient's body and, then, inserting the lead into the patient's body along the stylet. Each disclosed lead assembly uses one or more stents which expand to contact the inner surface of a body vessel once the lead has been properly positioned. Thus, the stents fix the lead at the desired location. Additionally, the stents may be used as electrodes for pacing and/or sensing.

Abstract: A catheter-based method for coronary sinus mapping, pacing, and ablation, wherein a flexible electrode catheter, having a tip electrode with suspension structure, is pre-shaped to snugly fit into the coronary sinus, so that the tip electrode is positioned into the sinus; the distal section is deflected to expose a predetermined plurality of electrodes; and RF energy is then applied to the coronary sinus tissue through the electrodes to cause activation mapping, and/or ablation.

Abstract: Systems and methods evaluate electrical contact between the myocardium and one or more electrodes inside the heart. The systems and methods electrically sense electrical contact between the myocardium and electrodes and generate unitary contact-indicating outputs indicating the presence or absence of electrical contact between the myocardium and each particular electrode. The systems and methods also correlate the electrode-specific unitary outputs to generate a compound contact-indicating output. The compound output represents the aggregate of the electrical contact between the myocardium and multiple electrodes on a multiple electrode array.

Abstract: A guide wire assembly comprises a tubular body having a distal end and an proximal end. At least a portion of the body comprises a single continuous helical spring to which one or more tubular electrodes are secured. The electrodes are insulated from the spring by means of an insulator. The electrodes can take a variety of forms, including conductive ribbons, longitudinally split conductive tubes, tubular sections, etc. The guide wire assembly may further include a variety of sensors, such as velocity sensors or temperature sensors. In order to allow flowable material to be passed to the distal end of the guide wire, the guide wire can include a catheter tube passable over the tubular body of the guide wire.

Abstract: An over-the-wire electrophysiology catheter which has an emitting electrode on the distal tip electrically connected to a source of high frequency electrical energy. The intravascular device is configured to be advanced through a patient's cardiac veins or coronary arteries and preferably is also provided with sensing electrodes for detecting electrical activity of the patient's heart from within a blood vessel of the heart. The device forms large lesions in tissue adjacent to the blood vessel in which the device is located without significantly damaging the blood vessel to effectively terminate signals causing arrhythmia.

Abstract: An RF ablation apparatus has a delivery catheter with distal and proximal ends. A handle is attached to the proximal end of the delivery catheter. The delivery catheter has an electrode deployment means where said electrode deployment means includes a retractable tip section comprising a deployable electrode with portion of one side having a sharp edge. The tip section has a non-deployed state when it is positioned in the delivery catheter. On the other hand, the tip section has a distended deployed state when it is advanced out of the distal end of said delivery catheter. The deployed tip section has a preformed shape while the farther distal deployed electrode defines an ablation target along with portion of the forward side having a sharp edge on said electrode. The forward edge of the deployed electrode has a slightly curvature or an essentially straight shape. Said deployable electrode has ultrasonic imaging capabilities.

Abstract: A parameter indicative of the status of fluid flow is remotely monitored in a vessel, a natural graft, or a synthetic graft. One or more transducers are provided either in a wall of a synthetic graft or adjacent to a vessel or natural graft to monitor the parameter. A conformal array transducer or a tilted element is used to monitor fluid flow or velocity through the graft or vessel based on the effect of the fluid on ultrasonic waves produced by the transducers. The conformal array transducer comprises a plurality of elements that curve around the graft or vessel and are excited with an input signal provided by an implantable electronics circuit, producing ultrasonic waves that propagate into the fluid flowing within the graft or vessel. Transit time or Doppler measurements are made using an appropriate number of these transducer to determine either fluid flow or velocity.

Abstract: An over-the-wire electrophysiology catheter which has an emitting electrode on the distal tip electrically connected to a source of high frequency electrical energy. The intravascular device is configured to be advanced through a patient's cardiac veins or coronary arteries and preferably is also provided with sensing electrodes for detecting electrical activity of the patient's heart from within a blood vessel of the heart. The device forms large lesions in tissue adjacent to the blood vessel in which the device is located without significantly damaging the blood vessel to effectively terminate signals causing arrhythmia.

Abstract: A catheter set includes a flexible catheter which is placed over a guide wire according to the Seldinger technique. A clamp is provided which can be laterally applied to the guide wire for tapping electrical potential from the guide wire. The clamp is laterally applied and directly attached to the proximal end of the guide wire when the distal portion of the guide wire is surrounded by the catheter and the tip of the guide wire protrudes from the catheter tip.

Abstract: An accessory pathway detecting apparatus measures action potentials from first and second electrode leads, and outputs the obtained action potentials, as potential maps, to a CRT or a printer such that the action potentials can be displayed in the form of a list. An ablation catheter is inserted and located at a preexcitation portion obtained from the display, and the impedance between each of the electrodes of the first and second electrode leads and the electrode of the ablation catheter is measured by an impedance measuring circuit. A point where the lowest impedance is measured is regarded as an accessory pathway portion. The ablation catheter is fixed at this point.