Abstract: Implant tools and techniques for implantation of a medical lead, catheter or other implantable component are provided. The implant tools and techniques are particularly useful in implanting medical electrical leads in implant locations such as substernal spaces or subcutaneous locations. The implant tools include a sheath coupled to a sealing device. The sheath includes a continuous lumen that is in fluid communication with a passage of the sealing device. The lead is advanced through the passage and the lumen for placement of the distal end of the lead at the implant location.

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: This disclosure provides an extravascular ICD system and method for defibrillating a heart of a patient. The extravascular ICD system includes multiple extravascular electrical stimulation leads or lead segments located in close proximity to one another and having respective defibrillation electrodes. The ICD system utilizes the multiple defibrillation electrodes to form an extravascular electrode vector that may result a reduction in the shock impedance and/or a reduction in the DFT compared to extravascular ICD systems that include only a single extravascular defibrillation electrode. An ICD of the system may, for example, deliver a defibrillation shock using an electrode vector in which a first polarity of the electrode vector is formed by electrically coupling first and second defibrillation electrodes of first and second leads, respectively, to the therapy circuitry and a second polarity of the electrode vector is formed by electrically coupling a housing of the ICD to the therapy circuitry.

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: This disclosure provides an extravascular ICD system and method for defibrillating a heart of a patient. The extravascular ICD system includes multiple extravascular electrical stimulation leads or lead segments located in close proximity to one another and having respective defibrillation electrodes. The ICD system utilizes the multiple defibrillation electrodes to form an extravascular electrode vector that may result a reduction in the shock impedance and/or a reduction in the DFT compared to extravascular ICD systems that include only a single extravascular defibrillation electrode. An ICD of the system may, for example, deliver a defibrillation shock using an electrode vector in which a first polarity of the electrode vector is formed by electrically coupling first and second defibrillation electrodes of first and second leads, respectively, to the therapy circuitry and a second polarity of the electrode vector is formed by electrically coupling a housing of the ICD to the therapy circuitry.

Abstract: Techniques and methods for determining the number and type of leads that are connected to an implantable medical device (IMD) system are disclosed. The IMD system is configured having at least two modes of operation, the modes of operation corresponding to the number and type of leads that are coupled to the IMD system. In accordance with aspects of the disclosure, one of the at least two modes may be selected based on the determination of the number and type of leads that are connected to the IMD system.

Abstract: A method and device for implanting a medical lead. The device includes an elongate shaft defining a major longitudinal axis and including a proximal end and a distal end. A necked portion coupled to and extending from the distal end is included, the necked portion defines a first thickness and a substantially planar surface, the necked portion being at least resiliently movable in a direction normal to the major longitudinal axis.

Abstract: A method for implanting a medical lead. The method includes advancing a tunneling tool posteriorly proximate the caudal end of the sternum toward a first location. The tunneling tool is advanced superiorly underneath the sternum through the anterior mediastinum from the first location to a second location cranial to the first location. A guidewire is advanced from the first location to the second location. A medical lead is slid along at least a portion of the guidewire, the medical lead at least substantially spanning the distance between the first location and the second location.

Abstract: A medical device and medical method. The medical device includes a flexible elongate body defining a proximal end and a distal end. The elongate body defines a first lumen spanning from the proximal end to a location proximal to the distal end. A shaping member insertable within the first lumen is included, the shaping member is configured to retain a manipulated shape when the flexible elongate body is manipulated from a first configuration to a second configuration. A tip is coupled to the distal end.

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: Implantable leadless cardiac pacing systems and methods for providing substernal pacing using the leadless cardiac pacing systems are described. In one embodiment, an implantable leadless cardiac pacing system includes a housing, a first electrode on the housing, a second electrode on the housing, and a pulse generator within the housing and electrically coupled to the first electrode and the second electrode. The housing is implanted substantially within an anterior mediastinum of a patient and the pulse generator is configured to deliver pacing pulses to a heart of the patient via a therapy vector formed between the first and second electrodes.

Abstract: Anchoring mechanisms for an implantable electrical medical lead that is positioned within a substernal space are disclosed. The anchoring mechanisms fixedly-position a distal portion of the lead, that is implanted in the substernal space.

Abstract: Techniques and methods for determining the number and type of leads that are connected to an implantable medical device (IMD) system are disclosed. The IMD system is configured having at least two modes of operation, the modes of operation corresponding to the number and type of leads that are coupled to the IMD system. In accordance with aspects of the disclosure, one of the at least two modes may be selected based on the determination of the number and type of leads that are connected to the IMD system.

Abstract: Implantable cardiac pacing systems and methods for providing substernal pacing are described. In one example, a cardiac pacing system includes a pacemaker implanted in a patient and an implantable medical electrical lead. The implantable medical electrical lead includes an elongated lead body having a proximal end and a distal portion, a connector configured to couple to the pacemaker at the proximal end of the elongated lead body, and one or more electrodes along the distal portion of the elongated lead body, wherein the distal portion of the elongated lead body of the lead is implanted substantially within an anterior mediastinum of the patient and the pacemaker is configured to deliver pacing pulses to a heart of the patient.

Abstract: Devices and implantation methods utilizing subcutaneous placement into a patient are disclosed for the insertion, advancement and positioning of a subcutaneous implantable medical device (SIMD) such as a medical electrical lead. The device for implanting the SIMD is configured having a pre-biased distal curve for creating a pathway to an implant location within a substernal space.

Abstract: An implantable cardiac defibrillator (ICD) system includes an ICD implanted subcutaneously in a patient, a defibrillation lead having a proximal portion coupled to the ICD and a distal portion having a defibrillation electrode configured to deliver a defibrillation or cardioversion shock to a heart of the patient, and a pacing lead that includes a distal portion having one or more electrodes and a proximal portion coupled to the ICD. The distal portion of the pacing lead is implanted at least partially along a posterior side of a sternum of the patient within the anterior mediastinum. The ICD is configured to provide pacing pulses to the heart of the patient via the pacing lead and provide defibrillation shocks to the patient via the defibrillation lead. As such, the implantable cardiac system provides pacing from the substernal space for an extravascular ICD system.

Abstract: Substernal implantable cardioveter-defibrillator (ICD) systems and methods for providing substernal electrical stimulation therapy to treat malignant tachyarrhythmia, e.g., ventricular tachycardia (VT) and ventricular fibrillation (VF) are described. In one example, an implantable cardioveter-defibrillator (ICD) system includes an ICD implanted in a patient and an implantable medical electrical lead. The lead includes an elongated lead body having a proximal end and a distal portion, a connector at the proximal end of the lead body configured to couple to the ICD, and one or more electrodes along the distal portion of the elongated lead body. The distal portion of the elongated lead body of the lead is implanted substantially within an anterior mediastinum of the patient and the ICD is configured to deliver electrical stimulation to a heart of the patient using the one or more electrodes.

Abstract: Implantable cardiac systems and methods for providing substernal pacing in an ICD system are described. In one example, an implantable cardiac system comprises an ICD system and an implantable leadless pacing device (LPD) communicatively coupled to the ICD system. The ICD system includes an ICD and an implantable defibrillation lead having a proximal portion coupled to the ICD and a distal portion having a defibrillation electrode configured to deliver a defibrillation shock to a heart of the patient. The LPD includes a housing, a first electrode on the housing, a second electrode on the housing, and a pulse generator within the housing and electrically coupled to the first electrode and the second electrode. The housing of the LPD is implanted substantially within an anterior mediastinum of the patient and the pulse generator is configured to deliver pacing pulses to a heart via the first and second electrodes.

Abstract: Implant tools and techniques for implantation of a medical lead, catheter or other implantable component are provided. The implant tools and techniques are particularly useful in implanting medical electrical leads in implant locations such as substernal spaces or subcutaneous locations. The implant tools include a sheath coupled to a sealing device. The sheath includes a continuous lumen that is in fluid communication with a passage of the sealing device. The lead is advanced through the passage and the lumen for placement of the distal end of the lead at the implant location.