Abstract: An extra-cardiovascular implantable cardioverter defibrillator (ICD) having a low voltage therapy module and a high voltage therapy module is configured to select, by a control module of the ICD, a pacing output configuration from at least a low-voltage pacing output configuration of the low voltage therapy module and a high-voltage pacing output configuration of the high voltage therapy module. The high voltage therapy module includes a high voltage capacitor having a first capacitance and the low voltage therapy module includes a plurality of low voltage capacitors each having up to a second capacitance that is less than the first capacitance. The ICD control module controls a respective one of the low voltage therapy module or the high voltage therapy module to deliver extra-cardiovascular pacing pulses in the selected pacing output configuration via extra-cardiovascular electrodes coupled to the ICD.

Abstract: An implantable medical device is configured to control a therapy module to couple a capacitor array comprising a plurality of capacitors to a plurality of extra-cardiovascular electrodes and control the therapy module to deliver a composite pacing pulse to a patient's heart via the plurality of extra-cardiovascular electrodes by sequentially discharging at least a portion of the plurality capacitors to produce a series of at least two individual pulses that define the composite pacing pulse.

Abstract: Described techniques include delivering cardiac pacing therapy from a medical device to a chamber of a heart via a first electrode configuration and determining that the delivery of cardiac pacing therapy via the first electrode configuration inadequately captures the chamber. In response to such a determination, the medical device delivers cardiac pacing therapy to the chamber of the heart via a plurality of additional electrode configurations. The techniques further comprise determining a capture characteristic for each of the additional electrode configurations based on the delivery of cardiac pacing therapy to the chamber of the heart via the plurality of other electrode configurations. A new electrode configuration for cardiac pacing may be selected based on the capture characteristics of the various electrode configurations.

Abstract: The disclosure describes techniques for evaluating sensing integrity of an implantable medical device (IMD) based on sensing of evoked signals. Sensing integrity may provide an indication of reliability of implantable leads associated with an IMD. The sensed signals may be signals that are evoked by tissue in response to delivery of electrical stimulation. The techniques may involve evaluation of sensing integrity based on sensing of evoked cardiac potentials generated in response to cardiac stimulation, such as pacing pulses. Signals evoked in response to electrical stimulation may be measured and trended to permit analysis of evoked signals over time. Lead integrity may be inferred from sensing integrity. By analyzing evoked signals, sensing integrity may be evaluated without sensing intrinsic events.

Abstract: A cardiac pacing device and method for automatically selecting an optimal evoked response sensing vector based on an evaluation of the evoked response signal quality are provided. Electrode switching circuitry allows selection of multiple sensing electrode vectors. Capture detection circuitry provides capture and loss of capture signal characteristics determined during a pacing threshold search to be used in determining evoked response signal quality parameters. An optimal evoked response sensing vector is selected based on evoked response signal quality parameters meeting predetermined criteria for reliable evoked response sensing.

Abstract: A cardiac pacing device and method for automatically selecting an optimal evoked response sensing vector based on an evaluation of the evoked response signal quality are provided. Electrode switching circuitry allows selection of multiple sensing electrode vectors. Capture detection circuitry provides capture and loss of capture signal characteristics determined during a pacing threshold search to be used in determining evoked response signal quality parameters. An optimal evoked response sensing vector is selected based on evoked response signal quality parameters meeting predetermined criteria for reliable evoked response sensing.

Abstract: A feedthrough configuration for a hermetically sealed implantable medical device which includes a metal case having an aperture and a feedthrough in the aperture which includes an electrically conductive pin, an insulating material supporting the pin, a block spaced from the case and in electrical continuity with the pin and a device for electrical protection connected to the block and to the case. The device for electrical protection preferably includes two zener diodes, a first diode connected at the block and a second diode connected to the case with an electrical conductor connecting the two diodes in a back-to-back configuration.

Abstract: A feedthrough configuration for a hermetically sealed implantable medical device includes a metal case having an aperture and a feedthrough in the aperture which includes a ferrule sealed in the aperture, a pin extending through the ferrule and the aperture, an insulating material supporting the pin within the ferrule and an electrically conductive block spaced from the ferrule and in electrical connection with the pin. A device for electrical or electromagnetic protection can be connected to a peripheral upstanding portion of the ferrule and a peripheral skirt portion of the block. This arrangement of feedthrough elements can be particularly useful if the protective device is a chip capacitor which typically has a flat-sided configuration that can bridge the space between the ferrule and the block and be connected at one end to the block and at the other end to the ferrule.

Abstract: A feedthrough configuration for a hermetically sealed implantable medical device which includes a metal case having an aperture and a feedthrough in the aperture which includes an electrically conductive pin, an insulating material supporting the pin, a block spaced from the case and in electrical continuity with the pin and a device for electrical protection connected to the block and to the case. The device for electrical protection preferably includes two zener diodes, a first diode connected at the block and a second diode connected to the case with an electrical conductor connecting the two diodes in a back-to-back configuration.