Abstract: An implantable medical device (IMD) can include a cardiac pacemaker or an implantable cardioverter-defibrillator (ICD). Various portions of the IMD, such as a device body, a lead body, or a lead tip, can be provided to reduce or dissipate a current and heat induced by various external environmental factors. According to various embodiments, features can be incorporated into the lead body, the lead tip, or the IMD body to reduce the creation of an induced current, or dissipate the induced current and heat created due to an induced current in the lead. For example, an IMD can include at least one outer conductive member and a first electrode. The first electrode can be in electrical communication with the at least one outer conductive member. The first electrode can dissipate a current induced in the at least one outer conductive member via a first portion of the anatomical structure.

Abstract: An extra-cardiovascular medical device is configured to select a capacitor configuration from a capacitor array and deliver a low voltage, pacing pulse by discharging the selected capacitor configuration across an extra-cardiovascular pacing electrode vector. In some examples, the medical device is configured to determine the capacitor configuration based on a measured impedance of the extra-cardiovascular pacing electrode vector.

Abstract: An implantable medical device is configured to control a therapy module to couple a capacitor array comprising a plurality of capacitors to a plurality of extra-cardiovascular electrodes and control the therapy module to deliver a composite pacing pulse to a patient's heart via the plurality of extra-cardiovascular electrodes by sequentially discharging at least a portion of the plurality capacitors to produce a series of at least two individual pulses that define the composite pacing pulse.

Abstract: An extra-cardiovascular implantable cardioverter defibrillator (ICD) having a low voltage therapy module and a high voltage therapy module is configured to select, by a control module of the ICD, a pacing output configuration from at least a low-voltage pacing output configuration of the low voltage therapy module and a high-voltage pacing output configuration of the high voltage therapy module. The high voltage therapy module includes a high voltage capacitor having a first capacitance and the low voltage therapy module includes a plurality of low voltage capacitors each having up to a second capacitance that is less than the first capacitance. The ICD control module controls a respective one of the low voltage therapy module or the high voltage therapy module to deliver extra-cardiovascular pacing pulses in the selected pacing output configuration via extra-cardiovascular electrodes coupled to the ICD.

Abstract: An extra-cardiovascular implantable cardioverter defibrillator (ICD) is configured to induce a tachyarrhythmia by charging a high voltage capacitor to a voltage amplitude and delivering a series of pulses to a patient's heart by discharging the capacitor via an extra-cardiovascular electrode vector. Delivering the series of pulses includes recharging the high-voltage capacitor during an inter-pulse interval between consecutive pulses of the series of pulses.

Abstract: This disclosure is directed to techniques for delivering cardiac pacing pulses to a patient's heart by a cardiac system, such as an extra-cardiovascular ICD system. An ICD operating according to the techniques disclosed herein delivers cardiac pacing pulses using high-voltage therapy circuitry typically configured for delivering high-voltage cardioversion/defibrillation shocks. The ICD delivers the high-voltage pacing therapy via extra-cardiovascular electrodes, such as one or more extra-cardiovascular electrodes carried by a medical electrical lead extending from the ICD and/or the housing of the ICD.

Abstract: A first shaft defining a proximal end, a distal end, and a first lumen there between sized to receive a medical lead. The first shaft includes a cutting element disposed at its distal end. The cutting element includes a sharp edge configured to mechanically cut tissue. A second shaft defining a proximal end, a distal end, and a second lumen there between is included. The second shaft co-axially surrounds the first shaft and is configured to slideably receive the first shaft. The second shaft includes a co-axial electrode extending from its distal end and configured to cut tissue with monopolar radiofrequency energy.

Abstract: A method and system for employing a medical device is disclosed. The medical device includes a housing, a processor disposed within the housing, a connector module, and a medical electrical epicardial lead connected to the processor through the connector module. The epicardial lead is used to sense a cardiac signal from tissue of a patient. The lead comprises an insulative lead body that includes a proximal end and a distal end, at least one conductor disposed in the lead body, and a side helical fixation member, disposed a distance from the distal end, the side helical fixation member. The side helical fixation member comprises a set of windings configured to wrap around the lead body circumference. The side helical fixation member includes a distal tip comprising a sharpened elongated flat free end that is perpendicular to the lead body and angled toward an inside of the set of windings.

Abstract: Selective sensing implantable medical leads include pulsing and sensing portions and pulsing and not sensing portion. Leads and electrodes may be used in defibrillation and as integrated bipolar defibrillation electrodes. An entire electrode can pass charge while a valve metal or valve metal oxide portion of the electrode prevents the entire electrode from sensing, effectively rejecting unwanted signals. Differential conduction pathways, due to the valve metal and/or oxides thereof, cause the portions of the electrodes to conduct differently when used anodically and cathodically. Complex intracardiac electrical gradient can be formed along with a number of virtual electrodes within the tissue. Reentrant loops can thereby be pinned following defibrillation shock.

Abstract: Selective sensing implantable medical leads include pulsing and sensing portions and pulsing and not sensing portion. Leads and electrodes may be used in defibrillation and as integrated bipolar defibrillation electrodes. An entire electrode can pass charge while a valve metal or valve metal oxide portion of the electrode prevents the entire electrode from sensing, effectively rejecting unwanted signals. Differential conduction pathways, due to the valve metal and/or oxides thereof, cause the portions of the electrodes to conduct differently when used anodically and cathodically. Complex intracardiac electrical gradient can be formed along with a number of virtual electrodes within the tissue. Reentrant loops can thereby be pinned following defibrillation shock.

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

Abstract: A medical access tool includes a needle member extending along a longitudinal axis, and a coiled wire extending around the axis. An inner surface of the coiled wire, along a proximal segment thereof, is spaced radially apart from an outer surface of the needle member, and a distal segment of the coiled wire extends distally to a tissue-engaging tip of the coiled wire, a piercing distal tip of the needle member being recessed proximally from the tissue-engaging tip at a fixed distance. An operator may rotate the coiled wire to engage tissue, for example, that of a pericardial sac or a diaphragmatic attachment, which then travels proximally along the coiled wire and into contact with the needle member's distal tip, to be pierced through thereby. At least one lumen of the needle member provides a passageway through which the operator may advance a guide wire and/or inject a fluid.

Abstract: An implantable medical electrical lead having an elongate lead body having a proximal end and a distal portion. A plurality of defibrillation electrodes coupled to the distal portion is included, the plurality of electrodes being transitionable from a first configuration in which the defibrillation electrodes are biased in an expanded configuration to a second configuration in which the defibrillation electrodes are in a collapsed configuration.

Abstract: This disclosure describes an implantable medical electrical lead and an ICD system utilizing the lead. The lead includes a lead body defining a proximal end and a distal portion, wherein at least a part of the distal portion of the lead body defines an undulating configuration. The lead includes a defibrillation electrode that includes a plurality of defibrillation electrode segments disposed along the undulating configuration spaced apart from one another by a distance. The lead also includes at least one electrode disposed between adjacent sections of the plurality of defibrillation sections. The at least one electrode is configured to deliver a pacing pulse to the heart and/or sense cardiac electrical activity of the heart.

Abstract: A lead body having a defibrillation electrode positioned along a distal portion of the lead body is described. The defibrillation electrode includes a plurality of electrode segments spaced a distance apart from each other. At least one of the plurality of defibrillation electrode segments includes at least one coated portion and at least one uncoated portion. The at least one coated portion is coated with an electrically insulating material configured to prevent transmission of a low voltage signal (e.g., a pacing pulse) while allowing transmission of a high voltage signal (e.g., a cardioversion defibrillation shock). The at least one uncoated portion is configured to transmit both low voltage and high voltage signals. The lead may also include one or more discrete electrodes proximal, distal or between the defibrillation electrode segments.

Abstract: The disclosure describes implantable medical systems that respond to occurrence of a lead-related condition by utilizing an elongated coil electrode in defining an alternative pacing therapy vector to maintain optimal drain of an IMD power supply. An exemplary system includes a medical electrical lead having an elongated electrode and an improved sensing and therapy delivery circuitry to provide the alternative pacing therapy vector responsive to the lead-related conditions. The system reconfigures the operation of the sensing and therapy delivery circuitry triggered by the switch to the alternative pacing therapy vector.

Abstract: Implantable medical electrical leads having electrodes arranged such that a defibrillation coil electrode and a pace/sense electrode(s) are concurrently positioned substantially over the ventricle when implanted as described. The leads include an elongated lead body having a distal portion and a proximal end, a connector at the proximal end of the lead body, a defibrillation electrode located along the distal portion of the lead body, wherein the defibrillation electrode includes a first electrode segment and a second electrode segment proximal to the first electrode segment by a distance. The leads may include at least one pace/sense electrode, which in some instances, is located between the first defibrillation electrode segment and the second defibrillation electrode segment.

Abstract: Implantable medical electrical leads having electrodes arranged such that a defibrillation coil electrode and a pace/sense electrode(s) are concurrently positioned substantially over the ventricle when implanted are described. The leads include an elongated lead body having a distal portion and a proximal end, a connector at the proximal end of the lead body, a defibrillation electrode located along the distal portion of the lead body, wherein the defibrillation electrode includes a first segment and a second segment proximal to the first segment by a distance, a first electrical conductor extending from the proximal end of the lead body and electrically coupling to the first segment and the second segment of the defibrillation electrode, and at least one pace/sense electrode located between the first segment and the second segment of the defibrillation electrode.

Abstract: A medical electrical lead includes an inductance augmenter assembly. The assembly includes an inductor coil formed of an insulated wire, which is wound about a non-conductive core and is electrically coupled in series between a conductor coil of the lead and an electrode of the lead.

Abstract: An implantable medical device (IMD) can include a cardiac pacemaker or an implantable cardioverter-defibrillator (ICD). Various portions of the IMD, such as a device body, a lead body, or a lead tip, can be provided to reduce or dissipate a current and heat induced by various external environmental factors. According to various embodiments, features can be incorporated into the lead body, the lead tip, or the IMD body to reduce the creation of an induced current, or dissipate the induced current and heat created due to an induced current in the lead. For example, an IMD can include at least one outer conductive member and a first electrode. The first electrode can be in electrical communication with the at least one outer conductive member. The first electrode can dissipate a current induced in the at least one outer conductive member via a first portion of the anatomical structure.