Abstract: A method for monitoring health of a subject based on a physiological response to physical exertion, by processing circuitry of a medical device system, is described that includes detecting a plurality of exertion events of the subject based on a first sensed signal that varies as a function of movement of the subject. The method further includes determining a response of a physiological parameter of the subject to the exertion event for each of the detected exertion events based on second sensed signal that varies as a function of the physiological parameter. The method further includes determining that a change in the responses over time crosses threshold and generating an alert to a user based on the determination that the change crosses the threshold.

Abstract: A technique for identifying lead-related conditions, such as insulation breaches and/or externalization of lead conductors, includes analyzing characteristics of electrical signals generated on one or more electrode sensing vectors of the lead by a test signal to determine whether a lead-related condition exists. The characteristics of the electrical signals induced on the lead by the test signal may be significantly different on a lead having an insulation breach or externalized conductor than on a lead not having such lead-related conditions. As such, the implantable medical device may be subject to a known test signal and analyze the signals on the lead to detect lead-related conditions.

Abstract: A medical device system and method for detecting dislodgement of a ventricular lead determines one or more characteristics of a cardiac signal received via the ventricular lead that are associated with dislodgement of the ventricular lead during atrial fibrillation, and detects dislodgement of the ventricular lead based on the determined characteristics. The medical device and system provides a lead dislodgment alert in response to detecting dislodgement. In some examples, an implantable medical device withholds delivery of a ventricular defibrillation therapy based on detecting dislodgement of the ventricular lead.

Abstract: The present disclosure is directed to an electrogram summary. In various examples, a subset of cardiac episodes are selected and displayed based on a set of summary rules. The subset of cardiac episodes includes at least one episode from each of a plurality of episode categories with at least one cardiac episode. In some examples, the order in which the cardiac episodes selected are displayed is based on the set of summary rules. The electrogram summary may include images or information regarding each of the selected cardiac episodes.

Abstract: An implantable medical device having a sensing module and a control module is configured to receive a cardiac electrical signal and sense events from the cardiac electrical signal received via electrodes carried by a medical electrical lead when the medical electrical lead is coupled to the implantable medical device. The control module coupled is configured to detect non-sustained tachyarrhythmia (NST) episodes based on sensed event intervals and determine if the sensed event intervals during the detected NST episode satisfy oversensing criteria. If the oversensing criteria are satisfied, the control module determines whether the detected NST episode satisfies non-lead related oversensing criteria and withholds a lead integrity alert when the NST episode meeting the oversensing criteria is determined to satisfy non-lead related oversensing criteria.

Abstract: An implantable medical device detects conditions such as a lead failure which may result in oversensing a physiologic condition. In response, the IMD automatically adjusts sensing thresholds, such as the number of intervals to detection in order to mitigate the effect of oversensing in the delivery of extraneous therapy.

Abstract: A medical device system and method for detecting cardiac lead dislodgement measures intervals between sensed cardiac events for detecting an event interval pattern including at least one short event interval consecutively followed by a long event interval. Responsive to detecting the event interval pattern, a cardiac signal amplitude associated with a detected short event interval is measured. Dislodgement of the cardiac lead is detected in response to the measured amplitude.

Abstract: An implantable medical device includes a sensing module configured to receive a cardiac electrical signal via electrodes carried by a medical electrical lead coupled to the implantable medical device and a control module configured to detect a lead issue. The sensing module is configured to produce cardiac sensed event signals and spike detect signals. The control module is configured to determine event intervals defined by consecutive ones of the received cardiac sensed event signals and the received spike detect signals and identify one or more received spike detect signals as lead issue spikes based on at least one of the determined event intervals.

Abstract: A method for delivering therapy in a medical device includes a two-tiered approach of determining the presence of a lead-related condition, and determining, in response to a lead-related condition being present, the presence of oversensing. Delivery of therapy by the medical device is controlled in response to determining that both the lead-related condition and oversensing are present.

Abstract: An implantable medical device is configured to detect saturation events from a cardiac electrical signal, detect a tachyarrhythmia based at least in part on the cardiac electrical signal, responsive to detecting the tachyarrhythmia, and compare the detected saturation events to lead issue criteria. If the detected saturation events satisfy lead issue criteria, a therapy for treating the tachyarrhythmia is withheld by the implantable medical device.

Abstract: Techniques for performing a lead integrity test in response to, e.g., during or after saturation of a sensed signal, e.g., a cardiac electrogram (EGM) signal, are described. A lead integrity test may comprise one or more impedance measurements for one or more leads. Possible causes of saturation of a sensed signal include lead conductor or connector issues, or other lead related conditions. A lead integrity test triggered in response to the saturation may be able to detect any lead related condition causing the saturation. A lead integrity test triggered in response to the saturation may advantageously be able to detect an intermittent lead related condition, due to the temporal proximity of the test to the saturation.

Abstract: A method and device for updating a frequency of determining whether a lead condition is occurring in a medical device that includes sensing a cardiac signal, determining whether a lead condition is occurring in response to the sensed cardiac signal, determining a patient characteristic, and updating a frequency of determining whether the lead condition is occurring in response to the determined patient characteristic.

Abstract: A method and device for updating a frequency of determining whether a lead condition is occurring in a medical device that includes sensing a cardiac signal, determining the number of days the lead has been implanted prior to implanting of the medical device, performing a first update of a virtual lead days value associated with a number of days since implant of the lead in response to the determined number of days the lead has been implanted prior to implanting of the medical device, determining whether a lead condition is occurring in response to the sensed cardiac signal, and updating a frequency of determining whether the lead condition is occurring in response to the determined first update of the virtual lead days value.

Abstract: A method and medical device for determining oversensing that includes sensing cardiac signals from a first sensing channel, determining whether oversensing of the cardiac signal is occurring in response the cardiac signals sensed from the first sensing channel, determining a sensing parameter adjustment and initiating sensing of cardiac signals from a second sensing channel having the adjusted sensing parameter in response to oversensing being determined to occur, determining an oversensing value in response to the sensing in the second sensing channel, and storing the determined oversensing value.

Abstract: A method and device for updating a frequency of determining whether a lead condition is occurring in a medical device that includes sensing a cardiac signal, determining whether a lead condition is occurring in response to the sensed cardiac signal, determining whether a first patient characteristic is satisfied during a plurality of predetermined update periods, performing a first update of a virtual lead days value associated with a number of days since implant of the lead in response to the first patient characteristic being satisfied, determining whether a patient characteristic update is satisfied in response to a second patient characteristic, different than the first patient characteristic, being satisfied, performing a second update of the virtual lead days value in response to the patient characteristic update being satisfied, and updating a frequency of determining whether the lead condition is occurring in response to the updated virtual lead days value.

Abstract: A method and medical device for determining oversensing that includes sensing cardiac signals from a first sensing channel, determining whether oversensing of the cardiac signal is occurring in response the cardiac signals sensed from the first sensing channel, determining a sensing parameter adjustment and initiating sensing of cardiac signals from a second sensing channel having the adjusted sensing parameter in response to oversensing being determined to occur, determining an oversensing value in response to the sensing in the second sensing channel, and storing the determined oversensing value.

Abstract: An implantable medical device capable of sensing cardiac signals and delivering cardiac electrical stimulation therapies is enabled to detect a short circuit condition on a sensing or therapy vector. A cardiac signal is sensed by a sensing module coupled to electrodes. A control module detects a short circuit condition in response to a significant drop in amplitude of far-field cardiac events coincident to near-field cardiac events. In some instances, the short circuit condition is detected in response an abnormal impedance on the far-field sensing vector and/or a matching morphology of the far-field cardiac electrical signal including the coincident FF cardiac event in addition to the significant drop in amplitude of the coincident FF cardiac events.

Abstract: A method and device for updating a frequency of determining whether a lead condition is occurring in a medical device that includes sensing a cardiac signal, determining the number of days the lead has been implanted prior to implanting of the medical device, performing a first update of a virtual lead days value associated with a number of days since implant of the lead in response to the determined number of days the lead has been implanted prior to implanting of the medical device, determining whether a lead condition is occurring in response to the sensed cardiac signal, and updating a frequency of determining whether the lead condition is occurring in response to the determined first update of the virtual lead days value.

Abstract: A method and device for updating a frequency of determining whether a lead condition is occurring in a medical device that includes sensing a cardiac signal, determining whether a lead condition is occurring in response to the sensed cardiac signal, determining a patient characteristic, and updating a frequency of determining whether the lead condition is occurring in response to the determined patient characteristic.

Abstract: A method and device for updating a frequency of determining whether a lead condition is occurring in a medical device that includes sensing a cardiac signal, determining whether a lead condition is occurring in response to the sensed cardiac signal, determining whether a first patient characteristic is satisfied during a plurality of predetermined update periods, performing a first update of a virtual lead days value associated with a number of days since implant of the lead in response to the first patient characteristic being satisfied, determining whether a patient characteristic update is satisfied in response to a second patient characteristic, different than the first patient characteristic, being satisfied, performing a second update of the virtual lead days value in response to the patient characteristic update being satisfied, and updating a frequency of determining whether the lead condition is occurring in response to the updated virtual lead days value.