A leadless pacemaker (100, 200, 300) and trailing (1, 3, 5) and leading (2, 4, 6) components thereof are disclosed. The trailing component (1, 3, 5) includes a first connecting member (12, 32) and a second connecting member (13), and the leading component (2, 4, 6) includes a third connecting member (23, 42, 62) and a fourth connecting member (24, 63). The first connecting member (12, 32) is configured to be detachably connected to the third connecting member (23, 42, 62) and the second connecting member (13) is configured to be detachably or non-detachably connected to the fourth connecting member (24, 63), thereby achieving interlocking between the trailing component (1, 3, 5) and the leading component (2, 4, 6). Additionally, both the first connecting member (12, 32) and the third connecting member (23, 42, 62) are non-biodegradable. At least one of the second connecting member (13) and the fourth connecting member (24, 63) is biodegradable, or the second connecting member (13) is fitted and connected to the fourth connecting member (24, 63) by an associated biodegradable connecting member. Thus, before the connecting member is degraded, it can be ensured that the trailing component (1, 3, 5) and the leading component (2, 4, 6) are firmly connected together by the four connecting members, facilitating overall retrieval or adjustment of the pacemaker (100, 200, 300). Moreover, after the connecting member is degraded, the trailing component (1, 3, 5) can be easily retrieved.

Systems and methods for cardiac pacing are provided, where a pacing lead is placed at or near the bundle of His. A method for pacing a heart of a patient comprises: introducing a sheath to vasculature of the patient; steering the sheath within a coronary sinus in the heart to lodge a distal end of the sheath to a target location proximal to the bundle of His above a septum separating a left ventricle and a right ventricle of the heart; advancing a pacing lead through a lumen of the sheath to the target location; coupling the pacing lead to cardiac tissue at the target location; removing the sheath; and electrically pacing the bundle of His using the pacing lead.

A leafless biostimulator, such as a leadless pacemaker, includes a housing sized and configured to be implanted within a heart of a patient and includes both primary and secondary fixation features. The primary fixation feature is adapted to rotate to fix the leadless biostimulator to a wall of the heart during initial implantation. Once the leadless biostimulator is implanted, the secondary fixation feature is adapted to resist counter-rotation of the leadless biostimulator. The primary fixation feature may include a fixation helix configured to affix the housing to the heart by rotating in a screwing direction. The secondary fixation feature may include an apex to engage the heart to resist unscrewing of the primary fixation feature.

Delivery devices, systems, and methods for delivering implantable leadless pacing devices are disclosed. An example delivery device may include an outer tubular member including a lumen extending from a proximal end to a distal end thereof and an intermediate tubular member including a lumen extending from a proximal end to a distal end thereof. A distal holding section may be coupled to the intermediate tubular member and define a cavity therein for receiving a proximal implantable leadless pacing device and a distal implantable leadless pacing device in a linear arrangement. The distal holding section may have a proximal body portion and a distal body portion. The proximal body portion may be more flexible than the distal body portion. An inner tubular member including a lumen extending from a proximal end to a distal end thereof may be slidably disposed within the lumen of the intermediate tubular member.

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.

An implantable leadless cardiac pacing device and associated retrieval features. The implantable device includes a docking member extending from the proximal end of the housing of the implantable device including a covering surrounding at least a portion of the docking member configured to facilitate retrieval of the implantable leadless cardiac pacing device.

One aspect is a method of fabricating a housing for an implantable medical device, including forming a first housing portion of metal using an additive manufacturing process such that features are integrated into the first portion. A second housing portion of metal is also formed. The first and second housing portions are joining thereby sealing an internal space of the housing within first and second portions and fully containing the features such that they are hermetically sealed relative to an external space outside the housing.

Method and system for determining an atrial contraction timing fiducial in a leadless cardiac pacemaker system is disclosed. An electrical cardiac signal associated with an atrial contraction of the patient's heart and a mechanical response to the atrial contraction of a patient's heart are used to determine an atrial contraction timing fiducial. A ventricle pacing pulse may then be generated an A-V delay after the atrial contraction timing fiducial.

Methods and systems for terminating a pacemaker mediated tachycardia (PMT) are described herein. During a period that a PMT is not detected, an implantable system delivers an atrial pacing pulse to an atrial cardiac chamber in response to a PA interval expiring without an intrinsic atrial event being detected during the PA interval. The systems performs atrial sensing to thereby monitor for intrinsic atrial events in the atrial cardiac chamber, performs ventricular sensing to thereby monitor for intrinsic ventricular events in a ventricular cardiac chamber, and detects the PMT. Additionally, the system, in response to the PMT being detected, initiates a PMT PA interval that is shorter than the PA interval that the system would otherwise use for atrial pacing if the PMT was not detected.

Disclosed herein is an implantable electronic device. In one embodiment, the device has a modular header-feedthru assembly and a housing. The modular header-feedthru assembly has a conductor assembly, a feedthru coupled to the conductor assembly, and a polymer header that is injected molded about the conductor assembly and at least a portion of the feedthru. The housing is welded to the feedthru.