An implantable medical system may provide atrioventricular synchronous pacing using the ventricular septal wall. The system may include a ventricular electrode coupled to an intracardiac housing or a first medical lead implantable in the ventricular septal wall of the patient's heart to deliver cardiac therapy to or sense electrical activity of the left ventricle of the patient's heart and a right atrial electrode coupled to a leadlet or second medical lead to deliver cardiac therapy to or sense electrical activity of the right atrium of the patient's heart. A right ventricular electrode may be coupled to the intracardiac housing or the first medical lead and implantable in the ventricular septal wall of the patient's heart to deliver cardiac therapy to or sense electrical activity of the right ventricle of the patient's heart.

An example device includes an elongated housing, a first and second electrode, and signal generation circuitry. The housing can be implanted within a single first chamber of the heart. The first electrode extends distally from the distal end of the elongated housing. A distal end of the first electrode can penetrate into wall tissue of a second chamber of the heart. The second electrode, extending from the distal end of the elongated housing, is configured to flexibly maintain contact with the wall tissue of the first chamber without penetration of the wall tissue of the first chamber by the second electrode. Signal generation circuitry can be within the elongated housing and coupled to the first and second electrode. The signal generation circuitry can deliver cardiac pacing to the second chamber via the first electrode and the first chamber via the second electrode.

Systems and methods for implanting a lead. The system includes an active guidewire having proximal and distal ends. The distal end includes a guidewire anchor that is configured to be attached to a target SOL. The active guidewire is configured to be utilized to electrically map the target SOI by at least one of delivering stimulation energy through the active guide wire to the target SOI or sensing an evoked response at the target SOI from the guidewire. The system also includes a lead having a lead body with proximal and distal ends and with a lumen extending between the proximal and distal ends. The distal end of the lead body is configured to receive the proximal end of the active guidewire. The lumen is configured to permit the lead body to be advanced over the active guidewire.

A leadless 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.

A device for the active fixation of an implantable medical lead includes a housing, a tine assembly, and rotatable shaft. The housing includes a proximal end for connecting to the lead and a distal end opposite the proximal end. The housing defines a housing lumen having a longitudinal axis extending between the proximal end and the distal end. The tine assembly is disposed within the housing lumen. The tine assembly includes at least one tine configured to self-bias from a linear configuration within the housing to a curved configuration outside of the housing. The rotatable shaft extends through the housing lumen. The shaft is configured to engage the tine assembly such that rotation of the shaft transitions the at least one tine between the linear configuration and the curved configuration.

The capsule comprises a tubular body and a front-end unit with an helical screw for anchoring the capsule to a wall of a patient's organ. The front-end unit is mobile in relative axial rotation with respect to the tubular body. A disengageable frictional coupling member allows this relative rotation when, for implantation, the tubular body receives an external rotational stress, and that until a predetermined limit torque triggering the disengagement. At explantation, this disengagement is prevented to allow a joint rotation of the tubular body and of the front-end unit and the unscrewing of the helical screw. It is provided for that purpose two conjugated plates facing each other, with flat surfaces such as circular sectors offset in opposite directions with respect to a radial reference plane, in such a way as to form steps providing an anti-disengagement abutment function.

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.

An implantable medical device system delivers a pacing pulse to a patient's heart and starts a first pacing interval corresponding to a pacing rate in response to the delivered pacing pulse. The system charges a holding capacitor to a pacing voltage amplitude during the first pacing interval. The system detects an increased intrinsic heart rate that is at least a threshold rate faster than the current pacing rate from a cardiac electrical signal received by a sensing circuit of the implantable medical device. The system starts a second pacing interval in response to an intrinsic cardiac event sensed from the cardiac electrical signal and withholds charging of the holding capacitor for at least a portion of the second pacing interval in response to detecting the increased intrinsic heart rate.

The device has a device body with a front face at its distal end, and a means for the anchoring of the medical device to a patient's organ wall. The anchoring means includes a screw with a helix wire wound into a plurality of non-contiguous turns, the screw having a clamped end integral with the front face of the device body and a free end with a beveled end defined by at least one oblique surface. The helix wire includes, at its free distal end, a terminal region whose wire bending stiffness is lower than in a proximal region of the helix turns. The stiffness difference may, in particular, be obtained by varying the wire diameter over different successive portions, with decreasing diameters in a proximal to distal direction.

A system implantable in the coronary venous system, including a pacing lead with an anchoring screw is disclosed. The system includes a stimulation lead (10) for stimulating a left heart cavity of a patient, and a removable catheter (26) for implanting the lead. The lead (10) has at least one stimulation electrode having an anchoring screw (14) that penetrates into the epicardial tissue of the patient. The catheter tube (26) is a pre-shaped tube with two curvatures in the absence of stress. The two curvatures are inscribed in two separate surfaces (38, 40) for self-orientating the distal end of the catheter tube into the target vein and maintaining the axis of the anchoring screw towards the epicardial wall during the screwing of the lead head.