Abstract: An implantable medical device capable of delivering high voltage therapy includes a therapy delivery module comprising a high voltage therapy delivery circuit, a high voltage short circuit protection circuit configured to terminate delivery of a high voltage pulse by the therapy delivery module in response to a short circuit condition, and a sensing module for detecting a need for a high voltage therapy. The device further includes a therapy control unit configured to control the therapy delivery module to deliver a shock pulse in response to detecting the need for the high voltage therapy. The control unit detects a termination of the high voltage pulse by the protection circuit; a truncated shock charge remaining on the high voltage therapy delivery circuit upon terminating the high voltage pulse. The control unit controls the therapy delivery module to deliver a next shock pulse at the remaining truncated shock charge.

Abstract: Methods and/or devices for modifying the sampling rate for measuring a patient's intrinsic AV conduction time during cardiac therapy. For example, the sampling rate for measuring a patient's intrinsic AV conduction time may be modified (e.g., decrease or increased) based on one or more monitored physiological parameters, such as activity level and/or heart rate.

Abstract: An implantable medical device operates according to a ventricular pacing protocol (VPP) that precludes ventricular pacing in any cardiac cycle where a sensed ventricular event has occurred in the preceding cycle. The implantable medical device facilitates improved ventricular sensing, detection and classification.

Abstract: An implantable cardiac pacing device delivering minimum ventricular pacing and an associated method control intervals timed by the device during sensing and pacing. An atrial-only pacing mode is set in response to sensing intrinsic ventricular events in the ventricular chamber. A first post-ventricular atrial refractory period is set following each of a plurality of ventricular events sensed in the ventricular chamber, and atrial events each being sensed during first post-ventricular atrial refractory periods are detected. A second post-ventricular atrial refractory period is set in response to detecting the atrial events each being sensed during the first post-ventricular atrial refractory period.

Abstract: Methods and/or devices for sampling a patient's intrinsic AV conduction time during cardiac therapy that may, e.g., change the AV delays to values based on the AV delays themselves, previously-sampled intrinsic AV conduction times, and/or one or more other parameters directly related to AV delays to provide a time period during which to measure the patient's intrinsic AV conduction time.

Abstract: Methods and/or devices for modifying the sampling rate for measuring a patient's intrinsic AV conduction time during cardiac therapy. For example, the sampling rate for measuring a patient's intrinsic AV conduction time may be modified (e.g., decrease or increased) based on one or more monitored physiological parameters, such as activity level and/or heart rate.

Abstract: An implantable cardiac pacing device delivering minimum ventricular pacing and an associated method control intervals timed by the device during sensing and pacing. An atrial-only pacing mode is set in response to sensing intrinsic ventricular events in the ventricular chamber. A first post-ventricular atrial refractory period is set following each of a plurality of ventricular events sensed in the ventricular chamber, and atrial events each being sensed during first post-ventricular atrial refractory periods are detected. A second post-ventricular atrial refractory period is set in response to detecting the atrial events each being sensed during the first post-ventricular atrial refractory period.

Abstract: An implantable medical device operates with an algorithm that promotes intrinsic conduction and reduces ventricular pacing. The IMD monitors the occurrence of necessary ventricular pacing and takes certain actions based upon whether this occurrence has been relatively high or relatively low. When noise is detected, asynchronous pacing is provided when the occurrence is relatively high and is not provided when relatively low. When atrial threshold testing is performed, the incidence will determine which methodology is utilized.

Abstract: Pacing parameters are provided to address cross talk and intrinsic ventricular events occurring within a predefined blanking period following an atrial event. The parameters are used in conjunction with protocol for minimizing or reducing ventricular pacing, wherein ignoring intrinsic ventricular events during the blanking period might otherwise affect the performance of the protocol.

Abstract: An implantable medical device operates with an algorithm that promotes intrinsic conduction and reduces ventricular pacing. The IMD monitors the occurrence of necessary ventricular pacing and takes certain actions based upon whether this occurrence has been relatively high or relatively low. When noise is detected, asynchronous pacing is provided when the occurrence is relatively high and is not provided when relatively low. When atrial threshold testing is performed, the incidence will determine which methodology is utilized.

Abstract: An implantable cardiac pacing device delivering minimum ventricular pacing and an associated method control intervals timed by the device during sensing and pacing. An atrial-only pacing mode is set in response to sensing intrinsic ventricular events in the ventricular chamber. A first post-ventricular atrial refractory period is set following each of a plurality of ventricular events sensed in the ventricular chamber, and atrial events each being sensed during first post-ventricular atrial refractory periods are detected. A second post-ventricular atrial refractory period is set in response to detecting the atrial events each being sensed during the first post-ventricular atrial refractory period.

Abstract: An implantable cardiac pacing device delivering minimum ventricular pacing and an associated method control intervals timed by the device during sensing and pacing. An atrial-only pacing mode is set in response to sensing intrinsic ventricular events in the ventricular chamber. A first post-ventricular atrial refractory period is set following each of a plurality of ventricular events sensed in the ventricular chamber, and atrial events each being sensed during first post-ventricular atrial refractory periods are detected. A second post-ventricular atrial refractory period is set in response to detecting the atrial events each being sensed during the first post-ventricular atrial refractory period.

Abstract: A pacing protocol is provided that reduces or minimizes ventricular pacing in favor of intrinsic conduction. When operating in a mode that provides ventricular pacing, a series of conduction checks are performed to determine if intrinsic conduction has returned. These conduction checks occur according to a predetermined pattern that general includes longer intervals between subsequent attempts. A maximum interval is provided such that conduction checks are not repeated sequentially at the same time of day when at this maximum interval.

Abstract: An implantable medical device operates according to a ventricular pacing protocol (VPP) that precludes ventricular pacing in any cardiac cycle where a sensed ventricular event has occurred in the preceding cycle. Improved ventricular sensing, detection and classification is provided.

Abstract: An implantable medical device operates according to a ventricular pacing protocol (VPP) that precludes ventricular pacing in any cardiac cycle where a sensed ventricular event has occurred in the preceding cycle. Improved ventricular sensing, detection and classification is provided.

Abstract: A pacing protocol is provided that reduces or minimizes ventricular pacing in favor of intrinsic conduction. When operating in a mode that provides ventricular pacing, a series of conduction checks are performed to determine if intrinsic conduction has returned. These conduction checks occur according to a predetermined pattern that generally includes longer intervals between subsequent attempts. The AV interval provided for dual chamber based pacing is modulated and generally moves from a larger value to a nominal value as the interval between unsuccessful conduction checks increases.

Abstract: An implantable medical device operates according to a ventricular pacing protocol (VPP) that precludes ventricular pacing in any cardiac cycle where a sensed ventricular event has occurred in the preceding cycle. Improved ventricular sensing, detection and classification is provided.

Abstract: An implantable medical device operates according to a ventricular pacing protocol (VPP) that precludes ventricular pacing in any cardiac cycle where a sensed ventricular event has occurred in the preceding cycle. Improved ventricular sensing, detection and classification is provided.

Abstract: Pacing parameters are provided to address cross talk and intrinsic ventricular events occurring within a predefined blanking period following an atrial event. The parameters are used in conjunction with protocol for minimizing or reducing ventricular pacing, wherein ignoring intrinsic ventricular events during the blanking period might otherwise affect the performance of the protocol.

Abstract: An implantable medical device operates according to a ventricular pacing protocol (VPP) that precludes ventricular pacing in any cardiac cycle where a sensed ventricular event has occurred in the preceding cycle. Improved ventricular sensing, detection and classification is provided.