Abstract: In some examples, a medical device delivery system includes a device cup configured to retain the medical device at the distal end of a catheter, the cup having a cylindrical body defining at least one vent hole extending from an exterior surface of the body to an interior surface of the body, and at least one internal rib extending inwardly from the interior surface, the rib configured to contact the medical device.

Abstract: In some examples, a medical device system includes an electrode. The medical device system may include impedance measurement circuitry coupled to the electrode, the impedance measurement circuitry may be configured to generate an impedance signal indicating impedance proximate to the electrode. The medical device system may include processing circuitry that may be configured to identify a first component of the impedance signal. The first component of the impedance signal may be correlated to a cardiac event. The processing circuitry may be configured to determine that the cardiac event occurred based on the identification of the first component of the impedance signal.

Abstract: An active return curve deflectable catheter includes an elongate member, a fixation member, a deflection assembly, and a pull wire. The fixation member is coupled to a distal portion of the elongate member. The deflection assembly includes a hub assembly coupled to a proximal end of the elongate member, a handle, and a control member. The pull wire extends from the control member through the hub assembly to the fixation member. The elongate member is configured to deflect from an initial configuration to a deflected configuration in response to a pull force applied to the pull wire by actuation of the control member in a first direction.

Abstract: A deflectable catheter includes an elongate member having a wall defining a longitudinally extending lumen extending from a proximal end to a distal end, a fixation member coupled to an exterior surface of the wall on a distal portion of the elongate member, and a pull wire extending through the wall of the elongate member from the proximal end of the elongate member to the fixation member. The pull wire is coupled to the fixation member and constrained along its length such that the elongate member is configured to deflect from an initial configuration to a deflected configuration in response to a pull force applied to the pull wire and actively return from the deflected configuration to the initial configuration in response to a push force applied to the pull wire.

Abstract: A device for delivering an implantable medical device (IMD) includes an elongated member and a deployment bay configured to house the IMD, the deployment bay defining a distal opening for deploying the IMD out of the deployment bay. The device includes a first electrode located inside the deployment bay during intravascular navigation, a second electrode, and impedance detection circuitry configured to deliver an electrical signal to a path between the first electrode and the second electrode through at least one of a fluid or tissue of the patient. The device also includes processing circuitry configured to determine an impedance of the path based on the signal and control a user interface to indicate when an impedance of the path indicates that at least one of the IMD or the distal opening is in a fixation configuration relative to the target site of the patient.

Abstract: A lead delivery apparatus and a method of delivering a medical lead to an anatomic target site. The method includes inserting a hydraulic plug into an internal delivery lumen of a delivery shaft, and coupling a medical lead to the hydraulic plug. Hydraulic pressure is applied to the hydraulic plug through the delivery lumen, thereby moving the hydraulic plug toward an anatomic target site, and advancing the medical lead toward the target site.

Abstract: In some examples, a tether head assembly of a delivery system includes an inner retainer and an outer retainer that defines an aperture comprising a receptacle configured to receive an attachment member of a medical device, a passageway, and a groove. The inner retainer is movable within the groove between a second position in which the passageway is dimensioned to receive the attachment member and a first position in which the passageway is dimensioned to prevent passage of the attachment member. In some examples, a tether handle assembly defines a channel, a force transmitter within the channel, a slidable member partially received within a first end of the channel and a button partially received within a second end of the channel. Distally-directed force applied to the button may cause the force transmitter to apply proximally-directed force to the slidable member, moving the slidable member and an attached pull wire proximally.

Abstract: In some examples, a tether head assembly of a delivery system includes an inner retainer and an outer retainer that defines an aperture comprising a receptacle configured to receive an attachment member of a medical device, a passageway, and a groove. The inner retainer is movable within the groove between a second position in which the passageway is dimensioned to receive the attachment member and a first position in which the passageway is dimensioned to prevent passage of the attachment member. In some examples, a tether handle assembly defines a channel, a force transmitter within the channel, a slidable member partially received within a first end of the channel and a button partially received within a second end of the channel. Distally-directed force applied to the button may cause the force transmitter to apply proximally-directed force to the slidable member, moving the slidable member and an attached pull wire proximally.

Abstract: A reservoir of a system for deploying an implantable lead to an extravascular location delivers a flow of fluid through a lumen of one or both of a tunneling tool and an introducer of the system. In some cases, the tunneling tool includes a pressure sensor assembly for monitoring a change in a pressure of the flow through the lumen thereof Alternately, or in addition, a flow-controlled passageway, through which the flow of fluid from the reservoir is delivered to the lumen of the introducer, includes a compliant chamber to hold a reserve of the fluid. Fluid from the reserve may be drawn into the lumen of the introducer as the tunneling tool is withdrawn therefrom. Alternately, the introducer may include a chamber located between two seals, wherein fluid that fills the chamber is drawn distally into the lumen of the introducer, as the tunneling tool is withdrawn therefrom.

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: This disclosure provides tools and implant techniques utilizing such tools to gain access to and implant a medical device, such as a medical electrical lead, within extravascular spaces. In one example, this disclosure provides a tool for creating a sub-sternal tunnel in a patient. The tool comprises a relatively straight guide member extending from a first end thereof to a second end thereof, a tunneling member extending from a first end thereof to a tip thereof, the tunneling member extending alongside and coplanar with the guide member, the first end of the tunneling member and the first end of the guide member being joined together, and a handle coupled to the guide member.

Abstract: A lead delivery apparatus and a method of delivering a medical lead to an anatomic target site. The method includes inserting a hydraulic plug into an internal delivery lumen of a delivery shaft, and coupling a medical lead to the hydraulic plug. Hydraulic pressure is applied to the hydraulic plug through the delivery lumen, thereby moving the hydraulic plug toward an anatomic target site, and advancing the medical lead toward the target site.

Abstract: A reservoir of a system for deploying an implantable lead to an extravascular location delivers a flow of fluid through a lumen of one or both of a tunneling tool and an introducer of the system. In some cases, the tunneling tool includes a pressure sensor assembly for monitoring a change in a pressure of the flow through the lumen thereof. Alternately, or in addition, a flow-controlled passageway, through which the flow of fluid from the reservoir is delivered to the lumen of the introducer, includes a compliant chamber to hold a reserve of the fluid. Fluid from the reserve may be drawn into the lumen of the introducer as the tunneling tool is withdrawn therefrom. Alternately, the introducer may include a chamber located between two seals, wherein fluid that fills the chamber is drawn distally into the lumen of the introducer, as the tunneling tool is withdrawn therefrom.

Abstract: This disclosure provides tools and implant techniques utilizing such tools to gain access to and implant a medical device, such as a medical electrical lead, within extravascular spaces. In one example, this disclosure provides a tool for creating a sub-sternal tunnel in a patient. The tool comprises a relatively straight guide member extending from a first end thereof to a second end thereof, a tunneling member extending from a first end thereof to a tip thereof, the tunneling member extending alongside and coplanar with the guide member, the first end of the tunneling member and the first end of the guide member being joined together, and a handle coupled to the guide member.

Abstract: Various techniques include advancing an implantable medical device comprising a tissue-piercing electrode toward the triangle of Koch region of the right atrium or through the coronary sinus to deliver cardiac therapy to or sense electrical activity of the left ventricle in the basal region, septal region, or basal-septal region of the left ventricular myocardium of a patient's heart. The tissue-piercing electrode may include an imageable material. The implantable medical device may include an imageable member made of an imageable material coupled to a housing or a lead of the implantable medical device. Image information representing the patient's heart and the imageable material may be acquired using two-dimensional imaging. Orientation information representing the implantable medical device may be generated based on the acquired image information.

Abstract: A method of delivering a pacing lead may include locating a potential implantation site adjacent to or within the triangle of Koch region of a patient's heart. The method may include advancing a pacing lead to the potential implantation site. The pacing lead has an elongate body and a fixation element coupled to a distal portion and attachable to the right-atrial endocardium adjacent to or within the triangle of Koch region. The method may include implanting the pacing lead at the potential implantation site to or sense electrical activity of the left ventricle in the basal and/or septal region of the left ventricular myocardium of the patient's heart. The pacing lead may include a lumen configured to receive a guide wire. A sheath of a delivery system used to deliver the pacing lead may include two or more curves to facilitate implanting the pacing lead at the implantation site.

Abstract: An example implantable medical device (IMD) retrieval system may include an elongate outer tubular member including a longitudinally extending lumen terminating in a distal cup that is configured to receive the IMD; and a retrieval assembly including a retrieval member that includes an elongate member terminating in at least one snare that is moveable between an expanded configuration and a contracted configuration; and a fixed-curve catheter that includes a resilient material forming a distal curve and defining a lumen in which the retrieval member extends in sliding engagement, where the fixed-curve catheter extends in sliding engagement within the lumen of the elongate outer tubular member.

Abstract: A device for delivering an implantable medical device (IMD) includes an elongated member and a deployment bay configured to house the IMD, the deployment bay defining a distal opening for deploying the IMD out of the deployment bay. The device includes a first electrode located inside the deployment bay during intravascular navigation, a second electrode, and impedance detection circuitry configured to deliver an electrical signal to a path between the first electrode and the second electrode through at least one of a fluid or tissue of the patient. The device also includes processing circuitry configured to determine an impedance of the path based on the signal and control a user interface to indicate when an impedance of the path indicates that at least one of the IMD or the distal opening is in a fixation configuration relative to the target site of the patient.

Abstract: An intracardiac ventricular pacemaker includes a pulse generator for delivering ventricular pacing pulses, an impedance sensing circuit, and a control circuit in communication with the pulse generator and the impedance sensing circuit. The pacemaker is configured to produce an intraventricular impedance signal, detect an atrial systolic event using the intraventricular impedance signal, set an atrioventricular pacing interval in response to detecting the atrial systolic event, and deliver a ventricular pacing pulse in response to the atrioventricular pacing interval expiring.

Abstract: An apparatus for forming a passageway through tissue includes a dilator mounted to a shaft, wherein the dilator includes a first portion, which has an increasing taper from a first outer diameter to a larger second outer diameter, and a second portion, which has a decreasing taper from the first portion to a distal end of the dilator, and which includes an external non-cutting thread formed along the decreasing taper. Lumens of the dilator and shaft provide a conduit for means to pierce through the tissue, for example, an elongate wire that includes a piercing tip. In some cases, the dilator first portion is expandable to, and contractible from, the larger second outer diameter, wherein the apparatus may include a spreading member configured to slide between the shaft and the first portion. The apparatus may be included in a system with an introducer sheath.