Abstract: A system to measure intracardiac impedance includes implantable electrodes and a medical device. The electrodes sense electrical signals of a heart of a subject. The medical device includes a cardiac signal sensing circuit coupled to the implantable electrodes, an impedance measurement circuit coupled to the same or different implantable electrodes, and a controller circuit coupled to the cardiac signal sensing circuit and the impedance measurement circuit. The cardiac signal sensing circuit provides a sensed cardiac signal. The impedance measurement circuit senses intracardiac impedance between the electrodes to obtain an intracardiac impedance signal. The controller circuit determines cardiac cycles of the subject using the sensed cardiac signal, and detects tachyarrhythmia using cardiac-cycle to cardiac-cycle changes in a plurality of intracardiac impedance parameters obtained from the intracardiac impedance 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: An implantable medical device senses a plurality of electrograms from substantially different atrial locations, detects regional depolarizations from the electrograms, and analyzes timing relationships among the regional depolarizations. The timing relationships provide a basis for effective therapy control and/or prognosis of certain cardiac disorders. In one embodiment, an atrial activation sequence is mapped to show the order of occurrences of the regional depolarizations during an atrial depolarization for classifying a detected tachyarrhythmia by its origin. In another embodiment, conduction time between two atrial locations is measured for monitoring the development of an abnormal atrial conditions and/or the effect of a therapy.

Abstract: A catheter includes a flexible tubing having a proximal end and a distal end. The catheter also includes an electrode assembly attached to the distal end of the flexible tubing and having a first magnet therein. The electrode assembly further includes an electrically conductive tip electrode and an electrically nonconductive coupler which is connected between the tip electrode and the distal end of the flexible tubing. The coupler and the tip electrode are coupled by an interlocking connection. The catheter also includes a second magnet spaced from the electrode assembly along a longitudinal axis of the tubing. The first magnet and the second magnet are responsive to an external magnetic field to selectively position and guide the electrode assembly within a body of a patient.

Abstract: A method for denervation comprises introducing a distal portion of a catheter through an interior of a vessel of a patient to a location at or proximate one of a renal pelvis or a calyx. The catheter includes an elongated catheter body extending longitudinally between a proximal end and a distal end. The catheter body includes the distal portion at the distal end and a catheter lumen from the proximal end to the distal end. Energy is delivered from the distal portion to cause renal denervation, for example, by denervating at least some tissue proximate at least one of the renal pelvis or a renal vessel from a location at or proximate the renal pelvis or the calyx from a location at or proximate the calyx.

Abstract: According to some method embodiments, a left pulmonary artery electrode is positioned in a left pulmonary artery, and the left pulmonary artery electrode is used to sense atrial activity, or capture cardiac tissue, or deliver neural stimulation. According to some method embodiments, a right pulmonary artery electrode is positioned in a right pulmonary artery and a left pulmonary artery electrode is positioned in a left pulmonary artery, the right pulmonary artery electrode is used to sense atrial activity, or capture cardiac tissue, or deliver neural stimulation, and the left pulmonary artery electrode is used to sense atrial activity, or capture cardiac tissue, or deliver neural stimulation.

Abstract: A system to measure intracardiac impedance includes implantable electrodes and a medical device. The electrodes sense electrical signals of a heart of a subject. The medical device includes a cardiac signal sensing circuit coupled to the implantable electrodes, an impedance measurement circuit coupled to the same or different implantable electrodes, and a controller circuit coupled to the cardiac signal sensing circuit and the impedance measurement circuit. The cardiac signal sensing circuit provides a sensed cardiac signal. The impedance measurement circuit senses intracardiac impedance between the electrodes to obtain an intracardiac impedance signal. The controller circuit determines cardiac cycles of the subject using the sensed cardiac signal, and detects tachyarrhythmia using cardiac-cycle to cardiac-cycle changes in a plurality of intracardiac impedance parameters obtained from the intracardiac impedance signal.

Abstract: A method and apparatus permit sensing one or more forces exerted by one or more portions of a heart. A force transducer and displacement sensor are disclosed. A movement of one or more portions of a heart can be translated into one or more signals indicative of force. These signals can be used to provide information such as to diagnose or treat one or more conditions.

Abstract: According to some method embodiments, a left pulmonary artery electrode is positioned in a left pulmonary artery, and the left pulmonary artery electrode is used to sense atrial activity, or capture cardiac tissue, or deliver neural stimulation. According to some method embodiments, a right pulmonary artery electrode is positioned in a right pulmonary artery and a left pulmonary artery electrode is positioned in a left pulmonary artery, the right pulmonary artery electrode is used to sense atrial activity, or capture cardiac tissue, or deliver neural stimulation, and the left pulmonary artery electrode is used to sense atrial activity, or capture cardiac tissue, or deliver neural stimulation.

Abstract: A transvenous renal nerve modulation system comprises: a blood pressure monitoring device to be implanted in a patient to monitor the patient's blood pressure; one or more transvenous renal nerve modulation leads to be implanted in one or more renal blood vessels of the patient; a pulse generator coupled to the transvenous renal nerve modulation leads to deliver electrical pulses to the one or more transvenous renal nerve modulation leads for modulating renal nerves of the patient; and a control unit coupled to the blood pressure monitoring device and the pulse generator to control delivery of the electrical pulses by the pulse generator based on the patient's blood pressure from the blood pressure monitoring device. The pulse generator delivers high frequency pulses of greater than about 10 Hz to the transvenous renal nerve modulation leads if the patient's blood pressure is greater than a high blood pressure threshold.

Abstract: A lead for nerve modulation comprises an elongated body which includes a proximal end, a distal portion having a distal end, and an intermediate portion disposed between the proximal end and the distal portion. The distal portion includes a distal portion anchoring mechanism to anchor the distal portion to a first biological cavity of a patient. The intermediate portion includes an intermediate portion anchoring mechanism to anchor the intermediate portion to a second biological cavity of the patient. The intermediate portion anchoring mechanism is larger in lateral dimension than and is spaced from the distal portion anchoring mechanism. The distal portion and/or the intermediate portion includes a plurality of modulation electrodes. The distal portion anchoring mechanism and/or the intermediate portion anchoring mechanism is configured to position the modulation electrodes to contact tissue of the patient at multiple locations.

Abstract: A catheter includes a flexible tubing having a proximal end and a distal end. The catheter also includes an electrode assembly attached to the distal end of the flexible tubing and having a first magnet therein. The electrode assembly further includes an electrically conductive tip electrode and an electrically nonconductive coupler which is connected between the tip electrode and the distal end of the flexible tubing. The coupler and the tip electrode are coupled by an interlocking connection. The catheter also includes a second magnet spaced from the electrode assembly along a longitudinal axis of the tubing. The first magnet and the second magnet are responsive to an external magnetic field to selectively position and guide the electrode assembly within a body of a patient.

Abstract: This document discusses, among other things, a lead body extending longitudinally along a lead axis, a driver axially displaceable relative to the lead body, and a driven member coupled to the lead body and displaceable away from the lead axis. The driven member at least partially defines an expandable passage having at least one internal dimension. The driver is displaceable into the expandable passage and has at least one outer dimension that is larger than the at least one internal dimension of the expandable passage. An example method includes disposing a first member having a first cross-section in a lead assembly having a lead axis, an expandable passage, and a displaceable member proximate the expandable passage. The method further includes urging the first member into the expandable passage in the lead assembly, and urging the displaceable member away from the lead axis to expand the expandable passage.

Abstract: Systems and methods for monitoring lung edema fluid status, such as monitoring the presence or absence of pulmonary edema, in a subject using information about responsive acoustic energy echoes from a lung are described. The system comprises, among other things, an implantable device including an acoustic transducer configured to emit acoustic energy to a lung and to receive one or more responsive acoustic energy echoes from a lung. In an example, the implantable device includes a cardiac function management device having an acoustic window in a body thereof. In another example, the implantable device includes one or more subcutaneous leads. An implantable or external processor circuit is configured to receive information about the acoustic energy echoes to compute and provide a lung edema fluid status indication; such information may include an increased number or special pattern of acoustic energy echoes received or a decreased time between successively received echoes.

Abstract: A catheter includes a flexible tubing having a proximal end and a distal end. The catheter also includes an electrode assembly attached to the distal end of the flexible tubing and having a first magnet therein. The electrode assembly further includes an electrically conductive tip electrode and an electrically nonconductive coupler which is connected between the tip electrode and the distal end of the flexible tubing. The coupler and the tip electrode are coupled by an interlocking connection. The catheter also includes a second magnet spaced from the electrode assembly along a longitudinal axis of the tubing. The first magnet and the second magnet are responsive to an external magnetic field to selectively position and guide the electrode assembly within a body of a patient.

Abstract: A pacing lead having a lead body configured into a pre-formed J-shape. The lead includes a pacing electrode coupled to an intermediate portion of the lead body and located distally from a bottom of the pre-formed J-shape. The lead is adapted to be placed within a heart in a J-shaped configuration with the electrode positioned proximate a ventricular septum or a right ventricular outflow tract such that at least a portion of the distal end of the lead body is located within a pulmonary artery. In one embodiment, the distal end of the lead is configured to be passively fixated within the pulmonary artery. Another aspect includes a lead body wherein a section of the intermediate portion of the lead body is less stiff than adjacent sections of the lead body. The lead includes a pacing electrode coupled to the intermediate portion of the lead body and located distally from the less stiff section.

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 in to 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: An implantable medical device senses a plurality of electrograms from substantially different atrial locations, detects regional depolarizations from the electrograms, and analyzes timing relationships among the regional depolarizations. The timing relationships provide a basis for effective therapy control and/or prognosis of certain cardiac disorders. In one embodiment, an atrial activation sequence is mapped to show the order of occurrences of the regional depolarizations during an atrial depolarization for classifying a detected tachyarrhythmia by its origin. In another embodiment, conduction time between two atrial locations is measured for monitoring the development of an abnormal atrial conditions and/or the effect of a therapy.

Abstract: Embodiments of the invention are related to implantable devices including movement sensors and related methods for measuring cardiac performance, amongst other things. In an embodiment, the invention includes an implantable electrical stimulation lead. The electrical stimulation lead can include a lead body having a proximal end and a distal end and a sheath defining a central lumen. The lead body can further include an electrical conductor disposed within the central lumen of the sheath. The stimulation lead can further include a stimulation electrode positioned at the distal end of the lead body, the stimulation electrode in electrical communication with the electrical conductor. The electrical stimulation lead can include an flexion sensor coupled to the lead body, the movement sensor configured to generate a signal in response to movement of the lead body. In an embodiment, the invention includes a method of monitoring the condition of a heart failure patient.

Abstract: An electrophysiology catheter for use with a steerable introducer sheath includes a flexible catheter body having a proximal end and a distal end and at least one hollow elongate tip electrode disposed at the distal end of the catheter body. The hollow elongate tip electrode includes a sidewall having at least one elongate gap that provides flexibility allowing the tip electrode to bend relative to a longitudinal axis of the catheter body. The catheter body is an independent, non-steerable structure, and can be moved via movement of the steerable introducer through which it is introduced into a patient.