Abstract: A leadless pacing system includes a leadless pacing device and a sensing extension extending from a housing of the leadless pacing device. The sensing extension includes one or more electrodes with which the leadless pacing device may sense electrical cardiac activity. The one or more electrodes of the sensing extension may be carried by a self-supporting body that is configured to passively position the one or more electrodes proximate or within a chamber of the heart other than the chamber in which the LPD is implanted.

Abstract: An implantable medical device includes an activity sensor, a pulse generator, and a control module. The control module is configured to determine activity metrics from the activity signal and determine an activity metric value at a predetermined percentile of the activity metrics. The control module sets a lower pacing rate set point based on the activity metric value at the predetermined percentile.

Abstract: A device includes a signal generator module, a processing module, and a housing. The signal generator module is configured to deliver pacing pulses to an atrium. The processing module is configured to detect a ventricular activation event and determine a length of an interval between the ventricular activation event and a previous atrial event that preceded the ventricular activation event. The processing module is further configured to schedule a time at which to deliver a pacing pulse to the atrium based on the length of the interval and control the signal generator module to deliver the pacing pulse at the scheduled time. The housing is configured for implantation within the atrium. The housing encloses the stimulation generator and the processing module.

Abstract: Techniques for minimizing rate of depletion of a non-rechargeable power source, to extend the operational lifetime of an implantable medical device that includes the non-rechargeable power source, by enforcing operational-mode-specific communication protocols whereby inter-device communication between the implantable medical device and another implantable medical device is such that level of power draw from the non-rechargeable power source by the implantable medical device is less than level of power draw from the rechargeable power source by the another implantable medical device for the implantable medical devices to engage in communication with each other.

Abstract: An intracardiac ventricular pacemaker is configured to operate in in a selected one of an atrial-tracking ventricular pacing mode and a non-atrial tracking ventricular pacing mode. A control circuit of the pacemaker determines at least one motion signal metric from the motion signal, compares the at least one motion signal metric to pacing mode switching criteria, and, responsive to the pacing mode switching criteria being satisfied, switches from the selected one of the non-atrial tracking pacing mode and the atrial tracking pacing mode to the other one of the non-atrial tracking pacing mode and the atrial tracking pacing mode for controlling ventricular pacing pulses delivered by the pacemaker.

Abstract: A medical device is configured to identify a first group of cardiac events, determine a cardiac event interval based on the first group of cardiac events and determine whether the cardiac event interval is less than a threshold interval or greater than the threshold interval. The medical device is configured to select a first blanking period duration if the cardiac event interval is less than the threshold interval or a second blanking period duration if the cardiac event interval is greater than the threshold interval.

Abstract: A medical device includes a motion sensor configured to sense a motion signal. The medical device includes a control circuit configured to determine at least one ventricular event metric from the motion signal sensed over multiple of atrial cycles, determine that the ventricular event metric meets atrioventricular block criteria and generate an output in response to determining the atrioventricular block.

Abstract: A system includes an implantable medical device (IMD) and processing circuitry. The IMD includes sensing circuitry configured to sense cardiac electrical signals of a patient, and therapy delivery circuitry configured to deliver demand cardiac pacing to a heart of the patient based on the cardiac electrical signals. The processing circuitry is configured to: determine, for each of a plurality of time units, based on the cardiac electrical signals and the delivery of demand cardiac pacing during the time units, a plurality of metrics indicative of a need for continued delivery of demand cardiac pacing to the heart of the patient. The plurality of metrics includes a metric associated with a duration of one or more pacing episodes during the time unit. The processing circuitry is further configured to generate a graphical representation of the plurality of metrics of the plurality of time units for presentation to a user.

Abstract: An implantable medical device system includes an extracardiac sensing device and an intracardiac pacemaker. The sensing device senses a P-wave attendant to an atrial depolarization of the heart via housing-based electrodes carried by the sensing device when the sensing device is implanted outside the cardiovascular system and sends a trigger signal to the intracardiac pacemaker in response to sensing the P-wave. The intracardiac pacemaker detects the trigger signal and schedules a ventricular pacing pulse in response to the detected trigger signal.

Abstract: A leadless pacing system includes a leadless pacing device and a sensing extension extending from a housing of the leadless pacing device. The sensing extension includes one or more electrodes with which the leadless pacing device may sense electrical cardiac activity. The one or more electrodes of the sensing extension may be carried by a self-supporting body that is configured to passively position the one or more electrodes proximate or within a chamber of the heart other than the chamber in which the LPD is implanted.

Abstract: A medical having a motion sensor is configured to set an atrial event sensing parameter used for sensing atrial event signals from a motion signal produced by the motion sensor. The medical device sets an atrial event sensing parameter by applying a sensing window during each one of multiple ventricular cycles, determining a feature of the motion signal during the sensing window for at least a portion of the ventricular cycles, and setting the atrial event sensing parameter based on the determined features. The medical device may sense the atrial event from the motion signal according to the atrial event sensing parameter.

Abstract: A medical device includes a motion sensor configured to sense a motion signal. The medical device includes a control circuit configured to determine if the motion signal sensed over a motion metric time interval meets oversensing criteria when a cardiac electrical event signal is received during the motion metric time interval.

Abstract: A medical device is configured to set a post-atrial time interval in response to an atrial event and generate an event time signal in response to a ventricular electrical signal crossing an R-wave sensing threshold during the post-atrial time interval. The device accumulates oversensing evidence in response to the event time signal and adjusts a ventricular sensing control parameter based on the accumulated oversensing evidence in some examples.

Abstract: A medical device is configured to sense a cardiac signal, determine a monitoring metric representative of activity of at least one heart chamber from the sensed cardiac signal, and determine that the monitoring metric meets expected rhythm criteria. The medical device may enable a monitoring feature of the medical device that is based on processing and analysis of the cardiac signal in response to the monitoring metric meeting the expected rhythm criteria.

Abstract: A medical device is configured to sense a first cardiac signal and a second cardiac signal and determine a quantitative relationship of a first feature of the first cardiac signal and a second feature of the second cardiac signal. The medical device is configured to confirm a sensed cardiac event signal and/or reject an oversensed signal based on the quantitative relationship.

Abstract: An implantable medical device system includes an extracardiac sensing device and an intracardiac pacemaker. The sensing device senses a P-wave attendant to an atrial depolarization of the heart via housing-based electrodes carried by the sensing device when the sensing device is implanted outside the cardiovascular system and sends a trigger signal to the intracardiac pacemaker in response to sensing the P-wave. The intracardiac pacemaker detects the trigger signal and schedules a ventricular pacing pulse in response to the detected trigger signal.

Abstract: A medical device is configured to identify a first group of cardiac events, determine a cardiac event interval based on the first group of cardiac events and determine whether the cardiac event interval is less than a threshold interval or greater than the threshold interval. The medical device is configured to select a first blanking period duration if the cardiac event interval is less than the threshold interval or a second blanking period duration if the cardiac event interval is greater than the threshold interval.

Abstract: An intracardiac ventricular pacemaker is configured to operate in in a selected one of an atrial-tracking ventricular pacing mode and a non-atrial tracking ventricular pacing mode. A control circuit of the pacemaker determines at least one motion signal metric from the motion signal, compares the at least one motion signal metric to pacing mode switching criteria, and, responsive to the pacing mode switching criteria being satisfied, switches from the selected one of the non-atrial tracking pacing mode and the atrial tracking pacing mode to the other one of the non-atrial tracking pacing mode and the atrial tracking pacing mode for controlling ventricular pacing pulses delivered by the pacemaker.

Abstract: A medical device is configured to sense a cardiac electrical signal and determine from the cardiac electrical signal at least one of a maximum peak amplitude of a positive slope of the cardiac electrical signal and a maximum peak time interval from a pacing pulse to the maximum peak amplitude. The device is configured to determine a capture type of the pacing pulse based on at least one or both of the maximum peak amplitude and the maximum peak time interval.

Abstract: Implantable medical systems enter an exposure mode of operation, either manually via a down linked programming instruction or by automatic detection by the implantable system of exposure to a magnetic disturbance. A controller then determines the appropriate exposure mode by considering various pieces of information including the device type including whether the device has defibrillation capability, pre-exposure mode of therapy including which chambers have been paced, and pre-exposure cardiac activity that is either intrinsic or paced rates. Additional considerations may include determining whether a sensed rate during the exposure mode is physiologic or artificially produced by the magnetic disturbance. When the sensed rate is physiologic, then the controller uses the sensed rate to trigger pacing and otherwise uses asynchronous pacing at a fixed rate.