A system may include a leadless cardiac pacing device including a body, a proximal hub, and a helical fixation member opposite the proximal hub; and a first elongate shaft having a lumen extending from a distal end of the elongate shaft proximally into the elongate shaft and a transverse member extending transversely across the lumen. The proximal hub may include a transverse channel extending into the proximal hub, the transverse channel being configured to engage the transverse member.

A pacemaker has a housing and a therapy delivery circuit enclosed by the housing for generating pacing pulses for delivery to a patient's heart. An electrically insulative distal member is coupled directly to the housing and at least one non-tissue piercing cathode electrode is coupled directly to the insulative distal member. A tissue piercing electrode extends away from the housing.

Delivery devices, systems, and methods for delivering implantable leadless pacing devices are disclosed. An example delivery device may include an intermediate tubular member and an inner tubular member slidably disposed within a lumen of the intermediate tubular member. A distal holding section may extend distally of a distal end of the intermediate tubular member and define a cavity therein for receiving an implantable leadless pacing device. The device may be configured to enable fluid flushing of the delivery device prior to use, to remove any air from within the device as well as providing the option of fluid flow during use of the delivery device.

A biostimulator delivery system having a tether cable, is described. A connector can be mounted on the tether cable to connect to a biostimulator. The connector can be a protuberance that lodges within the biostimulator, or a threaded connector that screws into the biostimulator. The tether cable has a stranded cable configuration, including several strands extending about a core strand in a helical direction. The stranded cable structure resists breaking under bending stresses typically seen during a tether mode used during delivery of the biostimulator. The tether cable reliably secures the biostimulator to the delivery system in the tether mode. Other embodiments are also described and claimed.

A medical lead system including an elongated lead body configured to extend through vasculature of a patient. The lead body mechanically supports a fixation member extending distal to a distal end of the lead body. A balloon is affixed to a distal portion of the lead body. The balloon is configured to inflate to extend distal to the distal end of the lead body. The fixation member is configured to extend within a distal cavity defined by the inflated balloon. The medical lead system is configured such that an electrode mechanically supported by the fixation member may electrically communicate with tissue of the patient when the balloon is in the inflated configuration.

An electrode assembly for the positioning of an electrode of an implantable medical lead includes a housing and an electrode subassembly. The housing includes a proximal end for connecting to the lead and a distal end. The housing defines a housing lumen extending between the proximal end and the distal end. The housing lumen includes internal screw threads extending along at least a portion of the housing lumen. The electrode subassembly is disposed at least partially within the housing lumen. The electrode subassembly includes a needle electrode and a coupler. The needle electrode is disposed coaxially with the longitudinal axis of the housing lumen. The coupler is disposed at a proximal end of the needle electrode. The coupler includes external screw threads engaged with the internal screw threads of the housing lumen such that rotation of the coupler moves the needle electrode along the longitudinal axis of the housing lumen.

A catheter tube comprises a tube wall, which surrounds a tube lumen, wherein the tube wall comprises the following: a mesh; and a guide lumen around which the mesh is braided and in which a pull element extends from a proximal portion of the catheter tube to a distal portion of the catheter tube. The pull element is connected in a tension-resistant manner to the tube wall in the distal portion. The guide lumen guides the pull element at least partially around the tube lumen.

An implantation and/or retrieval device for a leadless cardiac pacing device may include a first elongate shaft including a lumen; a second elongate shaft slidably disposed within the lumen of the first elongate shaft; an end cap assembly fixedly attached to a distal end of the first elongate shaft; and a plurality of wires attached to the second elongate shaft and extending distally from the end cap assembly, the plurality of wires being movable relative to the end cap assembly. The plurality of wires is configured to engage a proximal hub of the leadless cardiac pacing device. The plurality of wires forms a plurality of wire loops extending distally from the end cap assembly.

Systems and methods are provided for implanting a medical device. An implantable lead comprises a lead body, with electrodes positioned at the distal end and a lead connector positioned at the proximal end. The lead body has a body outer envelope configured to fit within a lumen of an introducer sheath and the lead connector has a connector outer envelope configured to fit within the lumen of the introducer sheath. A lead adaptor is configured to interconnect the implantable lead and the pulse generator. The lead adaptor has an insertable connector that includes mating contacts and an adaptor cavity that includes cavity contacts. The cavity contacts are positioned to engage the lead contacts of the lead connector when the lead connector is inserted into the adaptor cavity. The insertable connector is configured to be inserted into the connector cavity of the pulse generator.

In some examples, an implantable medical device (IMD) includes a housing defined in part by a longitudinal axis, a header at a distal end of the housing, the header defining a header plane, the header plane disposed at an angle relative to a reference plane, where the reference plane is perpendicular to the longitudinal axis, a fixation mechanism extending from the header, the fixation mechanism configured to be advanced into tissue of a heart of a patient to fix at least a portion of the IMD to the heart, one or more electrodes that extend from the header and are configured to engage with the septum, and circuitry within the housing, wherein the circuitry is configured to deliver cardiac pacing to the heart via the one or more electrodes.