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: 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: 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 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.

Abstract: A composition, article, and method for increasing the hydrolytic stability of a polymer; wherein a composition includes: a polymer comprising functional groups having hydrolyzable bonds; a carbodiimide compound; and a weak base (or hindered amine); wherein the carbodiimide compound and weak base (or hindered amine) are used in amounts effective to decrease the rate and/or extent of hydrolytic degradation of the polymer relative to either used alone in the same amount with the polymer.

Abstract: An implantable medical device includes ventricular and atrial portions, and a flexible leadlet that extends therebetween. An open channel of the atrial portion, formed along a core thereof, is sized to receive the leadlet therein, when the leadlet is folded over on itself. An interventional medical system includes the device and a delivery tool; a tubular sidewall of the tool defines a lumen and has a tether extending therein. A slot formed in the sidewall extends proximally from an open end thereof, coincident with a distal opening of the lumen. When the atrial portion is contained within the lumen, a segment of the leadlet extends alongside the atrial portion; another segment of the leadlet, being folded over on itself, proximal to the atrial portion, has the tether engaged therewith. The slot may allow passage of the leadlet therethrough, when the atrial portion is positioned for deployment through the distal opening.

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.

Abstract: A medical delivery device for delivering a medical device includes a navigable elongated member, a deployment bay, and a compression mechanism. The deployment bay may be configured to house the medical device as the medical device is navigated to the target site. The deployment bay may be at a distal end of the delivery device and may include a distal opening through which the medical device may be deployed. The compression mechanism is configured to longitudinally compress in response to a predetermined force such that the elongated member and deployment bay are relatively closer together along a longitudinal axis of the delivery device.

Abstract: This disclosure describes various tools and associated methods suitable for gaining access to extravascular spaces. The various tools and associated methods utilize a boring tip that may rotate to aid in safely and effectively crossing diaphragmatic attachments. The boring tip may, in some instances not have any sharp edge. For example, the boring tip may have a dome shape but including at least one surface recessed and offset from a summit of the dome shape. Various mechanisms may be used to control rotation of the boring tip as described herein.

Abstract: Methods and systems for positioning a leadless pacing device (LPD) in cardiac tissue are disclosed. A delivery device is employed that comprises a proximal end, a distal end and a lumen therebetween sized to receive the LPD. The LPD has a leadlet extending therefrom that includes a means to fixate the leadlet to tissue. The delivery device comprises an introducer to introduce the LPD into the lumen of the delivery device. The LPD is loaded in the distal end of the lumen of the delivery device. The leadlet extends proximally from the LPD while the fixation means extends distally toward the LPD. A LPD mover is configured to advance the LPD out of the delivery device. A leadlet mover is configured to advance the leadlet out of the lumen delivery device and cause the leadlet to engage with cardiac tissue.

Abstract: This disclosure describes various examples of multi-purpose tools and associated methods for safely gaining access to extravascular spaces. The multi-purpose tools described herein are particularly suited for safely gaining access to the sub-sternal space underneath the sternum/ribcage as well as tunneling subcutaneously above the ribcage for the purpose of positioning of a medical electrical lead. This eliminates the need for separate tools for tunneling in different extravascular spaces by providing a single tool capable of the multiple uses.

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: This disclosure describes various tools and associated methods suitable for gaining access to extravascular spaces. The various tools and associated methods utilize a boring tip that may rotate to aid in safely and effectively crossing diaphragmatic attachments. The boring tip may, in some instances not have any sharp edge. For example, the boring tip may have a dome shape but including at least one surface recessed and offset from a summit of the dome shape. Various mechanisms may be used to control rotation of the boring tip as described herein.

Abstract: Methods and systems for positioning a leadless pacing device (LPD) in cardiac tissue are disclosed. A delivery device is employed that comprises a proximal end, a distal end and a lumen therebetween sized to receive the LPD. The LPD has a leadlet extending therefrom that includes a means to fixate the leadlet to tissue. The delivery device comprises an introducer to introduce the LPD into the lumen of the delivery device. The LPD is loaded in the distal end of the lumen of the delivery device. The leadlet extends proximally from the LPD while the fixation means extends distally toward the LPD. A LPD mover is configured to advance the LPD out of the delivery device. A leadlet mover is configured to advance the leadlet out of the lumen delivery device and cause the leadlet to engage with cardiac tissue.

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 frequency component and a second frequency component of the impedance signal, and provide an indication of a location of the electrode in a patient based on the first frequency component and the second frequency component.

Abstract: An improved assembly for securing an implantable medical device for retrieval from an implant site includes a plurality of snares, wherein distal openings of a first snare carrier lumen and a second snare carrier lumen have a pre-set offset established therebetween. First and second snare shafts, to which first and second snare loops are coupled, respectively, extend within the corresponding snare carrier lumens such that each loop is located in proximity to the corresponding distal opening of the lumen. The pre-set offset allows an operator to simultaneously position the snare loops around the device; and, when the operator retracts the snare shafts to collapse the snare loops until the loops fit snuggly around the device, the pre-set offset can help to align the device for retrieval.

Abstract: The present disclosure is directed to a shuttle apparatus for detachably joining a catheter to a guidewire so that the joined catheter, extending alongside the guidewire, is in sliding engagement with the guidewire without extending around the guidewire. The apparatus comprises a collar member sized for mounting in sliding engagement around a length of the guidewire, the collar member having a longitudinal axis that approximately aligns along the length, when mounted thereabout, the length being defined between a proximal-most point of the guidewire and a distal point of the guidewire, the distal point being offset proximally from a distal-most point of the guidewire. The apparatus further comprises a plug member coupled to the collar member, the plug member having a longitudinal axis, and the plug member being sized to fit within an opening of the catheter for detachable engagement therewith.

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.