Methods, systems, and devices for signal analysis in an implanted cardiac monitoring and treatment device such as an implantable cardioverter defibrillator. In some examples, captured data including detected events is analyzed to identify likely overdetection of cardiac events. In some illustrative examples, when overdetection is identified, data may be modified to correct for overdetection, to reduce the impact of overdetection, or to ignore overdetected data. Several examples emphasize the use of morphology analysis using correlation to static templates and/or inter-event correlation analysis.

An implantable neurostimulator-implemented method for managing tachyarrhythmias through vagus nerve stimulation is provided. An implantable neurostimulator, including a pulse generator, is configured to deliver electrical therapeutic stimulation in a manner that results in creation and propagation (in both afferent and efferent directions) of action potentials within neuronal fibers of a patient's cervical vagus nerve. Operating modes of the pulse generator are stored. A maintenance dose of the electrical therapeutic stimulation is delivered to the vagus nerve via the pulse generator to restore cardiac autonomic balance through continuously-cycling, intermittent and periodic electrical pulses. A restorative dose of the electrical therapeutic stimulation is delivered to prevent initiation of or disrupt tachyarrhythmia through periodic electrical pulses delivered at higher intensity than the maintenance dose. The patient's normative physiology is monitored via a physiological sensor, and upon sensing a condition indicative of tachyarrhythmia, is switched to delivering the restorative dose to the vagus nerve.

A sheath adapted for use with a catheter is disclosed comprising an electrical lead having a proximal end and a distal end and a lumen extending from the proximal end to the distal end, the electrical lead including a tubular member of non-conductive material. At least a first set of electrical conductors and a second set of electrical conductors extend from the proximal end to the distal end laid on the non-conductive tubular member, and an outer layer of non-conductive material is applied over the electrical conductors to cover the conductors. One or more electrodes are disposed on a distal portion of the sheath. Each electrode is in electrical communication with at least one of the electrical conductors through the outer layer. The first set of electrical conductors is helically wrapped around the lumen and the second set of electrical conductors is helically wrapped around the first set of electrical conductors.

A catheter configured to deliver therapeutic energy to a tissue can include can include an elongate shaft extending along a shaft longitudinal axis and comprising a shaft proximal end and a shaft distal end. The catheter can include a flexible tip assembly comprising a tip assembly outer surface, wherein the flexible tip assembly is connected to the shaft distal end and is configured to deliver therapeutic energy to the tissue, and wherein the flexible tip assembly further includes. The flexible tip assembly can include an insulative layer comprising an insulative layer outer surface, wherein the insulative layer is disposed on the tip assembly outer surface and a mapping electrode disposed on the insulative layer outer surface.

Cardiac electrograms are recorded in a plurality of channels. Beats are classified automatically into respective classifications according to a resemblance of the morphologic characteristics of the beats to members of a set of templates. Respective electroanatomic maps of the heart are generated from the classified beats.

An apparatus comprises a respiration sensing circuit configured for coupling electrically to a plurality of electrodes and for sensing a respiration signal representative of respiration of a subject; a signal processing circuit electrically coupled to the respiration sensing circuit and configured to extract a respiration parameter from a sensed respiration signal and determine a signal performance metric for the sensed respiration signal using the respiration parameter; and a control circuit. The control circuit is configured to: initiate sensing of a plurality of respiration signals using different electrode combinations of the plurality of electrodes and determining of the signal performance metric for the sensed respiration signals; and enable an electrode combination from the plurality of electrodes and for use in monitoring respiration of the subject according to the signal performance metric.

Navigation and tissue capture systems and methods for navigation to and/or capture of selected tissue using the innate electrical activity of the selected tissue and/or other tissue are described. In the context of left atrial appendage closure, the systems and methods can be used to navigate to the left atrial appendage and capture/control the appendage while a closure instrument (suture, clip, ring) is placed over the appendage and tightened down or a closure method (ablation, cryogenic procedures, stapling, etc.) is performed to close the left atrial appendage. The use of innate electrical activity for navigating devices may be used in connection with other tissues and/or areas of the body.

An expandable electrode assembly for use in a cardiac mapping procedure includes multiple bipolar electrode pairs including a first electrode located on an outer surface and a second electrode located on an inner surface of the individual splines forming the expandable electrode assembly. Such an electrode arrangement may produce improved electrical activation signals which may be used to produce a more accurate map of the electrical activity of a patient's heart.

A catheter with three distinct compression resistance coils, including a body coil and two pull wire coils, is disclosed. The triple coil system can provide maximal resistance to compression of the catheter's proximal shaft, as well as maximization of the curve angle that the catheter tip can achieve. Additionally, the tri-coil catheter can allow for a lower initial compression load and a more flexible proximal shaft. A gap between the outer diameter of the pull wire and the inner diameter of the pull wire compression coil that is equal to about 10-30% of inner diameter of the pull wire compression coil can provide optimal catheter performance.

Described embodiments include a catheter, which includes a plurality of splines at a distal end of the catheter, and a plurality of helical conducting elements disposed on the splines. Other embodiments are also described.