Abstract: An implantable medical device system receives a cardiac electrical signal produced by a patient's heart and comprising atrial P-waves and delivers a His bundle pacing pulse to the patient's heart via a His pacing electrode vector. The system determines a timing of a sensed atrial P-wave relative to the His bundle pacing pulse and determines a type of capture of the His bundle pacing pulse in response to the determined timing of the atrial P-wave.

Abstract: A medical device includes a motion sensor for producing a motion signal including cardiac event signals. The medical device generates a ventricular pacing pulse upon expiration of a pacing interval. The medical device determines a synchrony metric from the motion signal after a delivered ventricular pacing pulse and adjusts the pacing interval based on the synchrony metric.

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.

Abstract: The control module of a first pacemaker included in an implantable medical device system including the first pacemaker and a second pacemaker is configured to set a pacing escape interval in response to a far field pacing pulse sensed by the first pacemaker. The far field pacing pulse is a pacing pulse delivered by the second pacemaker. The pacing escape interval is allowed to continue without restarting the in response to a far field intrinsic event sensed by the first pacemaker during the pacing escape interval. The first pacemaker delivers a cardiac pacing pulse to the heart upon expiration of the pacing escape interval.

Abstract: A medical device is configured to generate an acceleration signal and a temperature signal. The device is configured to determine an activity metric from the acceleration signal that is representative of patient physical activity. In response to determining that the activity metric is equal to or greater than a previously determined activity metric, the device is configured to adjust a target cardiac pacing rate based at least on a temperature change determined from the temperature signal. The device may include a pulse generator for generating cardiac pacing pulses based on the target cardiac pacing rate.

Abstract: An implantable medical device is configured to determine a first atrial arrhythmia score from ventricular events sensed by a sensing circuit of an implantable medical device and determine a second atrial arrhythmia score from an intraventricular signal comprising atrial mechanical event signals attendant to atrial systole and produced by a sensor of the implantable medical device. An atrial arrhythmia is detected based on the first atrial arrhythmia score and the second atrial arrhythmia score.

Abstract: An implantable medical device system receives a cardiac electrical signal produced by a patient's heart and comprising atrial P-waves and delivers a His bundle pacing pulse to the patient's heart via a His pacing electrode vector. The system determines a timing of a sensed atrial P-wave relative to the His bundle pacing pulse and determines a type of capture of the His bundle pacing pulse in response to the determined timing of the atrial P-wave.

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: The control module of a first pacemaker included in an implantable medical device system including the first pacemaker and a second pacemaker is configured to set a pacing escape interval in response to a far field pacing pulse sensed by the first pacemaker. The far field pacing pulse is a pacing pulse delivered by the second pacemaker. The pacing escape interval is allowed to continue without restarting the in response to a far field intrinsic event sensed by the first pacemaker during the pacing escape interval. The first pacemaker delivers a cardiac pacing pulse to the heart upon expiration of the pacing escape 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.

Abstract: A medical device includes a motion sensor configured to produce a motion signal and a control circuit configured to set sensing control parameters and sense atrial events from the motion signal during ventricular cycles according to the sensing control parameters. In some examples, the control circuit is configured to determine a feature of the motion signal for at least some ventricular cycles, determine a metric of the motion signal based on the determined features, and adjust at least one of the sensing control parameters based on the metric.

Abstract: A pacemaker having a motion sensor is configured to select an atrial event sensing vector of a multi-axis motion sensor for sensing atrial systolic events from a motion signal produced by the motion sensor. In some examples, the pacemaker determines a maximum amplitude during a sensing window for each one of multiple vector signals produced by the multi-axis motion sensor. The pacemaker may select the atrial event sensing vector signal from among the vector signals based on the determined maximum amplitudes.

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: 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: Ventricle-from-atrium (VfA) devices, systems, and methods may be configured to monitor a single channel of cardiac electrical activity and determine atrial events and ventricular events based on the single channel of cardiac electrical activity. Various processing, windowing, and thresholding may be used to identify atrial events and ventricular events within the single channel of cardiac electrical activity.

Abstract: A medical device includes a motion sensor configured to produce a motion signal and a control circuit configured to sense atrial events from the motion signal. In some examples, the control circuit is configured to set a ventricular diastolic event window and set a threshold amplitude during the ventricular diastolic event window for sensing an atrial event in response to the motion signal crossing the threshold amplitude during the ventricular diastolic window. The control circuit may determine a maximum amplitude of the motion signal during the ventricular diastolic event window for multiple ventricular cycles and determine an amplitude metric based on at least a portion of the determined maximum amplitudes. The control circuit may determine a target value of the threshold amplitude based on at least the amplitude metric and adjust the threshold amplitude toward the target value.

Abstract: A pacemaker having a motion sensor delivers atrial-synchronized ventricular pacing by detecting events from a signal produced by the motion sensor and delivering ventricular pacing pulses at a rate that tracks the rate of the detected events. The pacemaker is configured to confirm atrial tracking of the ventricular pacing pulses by determining if detected events from the motion sensor signal are atrial events. The pacemaker is configured to adjust a control parameter used for detecting events from the motion sensor signal if atrial tracking is not confirmed.

Abstract: A medical device includes a motion sensor configured to produce a motion signal and a control circuit configured to set sensing control parameters and sense atrial events from the motion signal during ventricular cycles according to the sensing control parameters. In some examples, the control circuit is configured to determine a feature of the motion signal for at least some ventricular cycles, determine a metric of the motion signal based on the determined features, and adjust at least one of the sensing control parameters based on the metric.

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.

Abstract: A pacemaker having a motion sensor is configured to set atrial event sensing parameters used for sensing atrial systolic events from a motion signal produced by the motion sensor. The pacemaker sets at least one atrial event sensing parameter by identifying ventricular electrical events and setting a sensing window following each of the ventricular electrical events. The pacemaker may determine a feature of the motion signal produced by the motion sensor during each of the sensing windows and set the atrial event sensing parameter based on the determined features.