A medical device is configured to receive cardiac electrical signals and sense ventricular event signals from the cardiac electrical signals. The medical device may start a validation window in response to sensing a ventricular event signal and determine if the ventricular event signal is a valid event signal or an invalid event signal based on processing of a different cardiac electrical signal than the cardiac electrical signal from which the ventricular event signal was sensed.

A pacing device, a system comprising the pacing device and a method for operation of the pacing device, wherein the pacing device comprises a housing, a processor and a receiver electrically connected to the processor, wherein the processor is adapted to deliver signals for electric stimulation of a patient's heart according to at least one first stimulation mode and deliver signals for electric stimulation of the patient's heart according to an antitachycardiac pacing mode (ATP mode), wherein the ATP mode is initially deactivated and/or is to be upgraded, wherein the receiver is adapted to receive an ATP confirmation signal transmitted by an external device or produced by operation of an actuator accommodated at the housing of the pacing device, wherein the processor is adapted to upgrade the ATP mode and/or to activate the ATP mode only if the ATP confirmation signal comprises a pre-defined confirmation information.

An implantable medical device system delivers a pacing pulse to a patient's heart and starts a first pacing interval corresponding to a pacing rate in response to the delivered pacing pulse. The system charges a holding capacitor to a pacing voltage amplitude during the first pacing interval. The system detects an increased intrinsic heart rate that is at least a threshold rate faster than the current pacing rate from a cardiac electrical signal received by a sensing circuit of the implantable medical device. The system starts a second pacing interval in response to an intrinsic cardiac event sensed from the cardiac electrical signal and withholds charging of the holding capacitor for at least a portion of the second pacing interval in response to detecting the increased intrinsic heart rate.

Described herein are methods, devices, and systems that improve arrhythmia episode detection specificity, such as, but not limited to, atrial fibrillation (AF) episode detection specificity. Such a method can include obtaining an ordered list of R-R intervals within a window leading up to a detection of a potential arrhythmia episode, determining a measure of a dominant repeated R-R interval pattern within the window, and comparing the measure of the dominant repeated R-R interval pattern to a pattern threshold. If the measure of the dominant repeated R-R interval pattern is below the pattern threshold, that is indicative of a regularly irregular pattern being present, and there is a determination that the detection of the potential arrhythmia episode does not correspond to an actual arrhythmia episode. Such embodiments can beneficially be used to significantly reduce the number of false positive arrhythmia detections.

A medical device is configured to determine an amplitude metric from a cardiac signal segment sensed over a predetermined time interval and determine if the amplitude metric meets an amplitude threshold. The medical device is configured to perform a first analysis of the cardiac electrical signal segment for detecting a first arrhythmia when the amplitude metric does not meet the amplitude threshold and perform a second analysis of the cardiac electrical signal segment for detecting a second arrhythmia different than the first arrhythmia in response to the amplitude metric meeting the amplitude threshold.

Described herein are methods, devices, and systems that monitor heart rate and/or for arrhythmic episodes based on sensed intervals that can include true R-R intervals as well as over-sensed R-R intervals. True R-R intervals are initially identified from an ordered list of the sensed intervals by comparing individual sensed intervals to a sum of an immediately preceding two intervals, and/or an immediately following two intervals. True R-R intervals are also identified by comparing sensed intervals to a mean or median of durations of sensed intervals already identified as true R-R intervals. Individual intervals in a remaining ordered list of sensed intervals (from which true R-R intervals have been removed) are classified as either a short interval or a long interval, and over-sensed R-R intervals are identified based on the results thereof. Such embodiments can be used, e.g., to reduce the reporting of and/or inappropriate responses to false positive tachycardia detections.

An active implantable medical device includes a detection electrode and a pulse generator. The pulse generator is configured to collect via the detection electrode at least two EGM signals, combine the EGM signals into two time components, and combine the components into a single 2D parametric characteristic representing the cardiac cycle. During a tachyarrhythmia episode, the device measures stores values of a cycle-to-cycle variation in an amplitude of the at least one of the EGM signals, distributes the amplitude variation values into a plurality of classes, each class corresponding to an amplitude interval, and analyzes a size of each of the plurality of classes to deliver at least one of an indicator of suspicion of an artifact of extracardiac origin or an indicator of a type of tachyarrhythmia selectively as a function of at least one predetermined criterion applied to the distribution of the amplitude variation values.

An implantable system for the diagnostic and/or therapeutic treatment of a human or animal patient contains a processor, a memory, a treatment unit and a remote data transmission unit. The system is characterized in that the memory includes a computer-readable program which prompts the processor to carry out the following steps when the program is being executed on the processor: a) ascertaining whether a treatment functionality of the treatment unit could jeopardize a patient in whom the system was implanted if a diagnostic and/or therapeutic treatment of the patient corresponding to the treatment functionality were to be carried out; b) deactivating the treatment functionality when a potential risk for the patient was ascertained; c) receiving reactivation data by way of the remote data transmission unit; and d) reactivating the deactivated treatment functionality based on the received reactivation data.

An example medical device system includes an implantable medical lead including a first defibrillation electrode and a second defibrillation electrode, the first and second defibrillation electrodes configured to deliver antitachyarrhythmia shocks, and a pace electrode disposed between the first defibrillation electrode and the second defibrillation electrode, the pace electrode configured to deliver a pacing pulse that generates an electric field proximate to the pace electrode. The medical device system includes a shield configured to be implanted in a patient separately from the implantable medical lead and disposed anterior at least one of the electrodes, wherein the shield is configured to impede an electric field of the electrical therapy in a direction from at least one of the first defibrillation electrode, the second defibrillation electrode, or the pace electrode away from a heart of the patient.

An example device for detecting one or more parameters of a cardiac signal is disclosed herein. The device includes one or more electrodes and sensing circuitry configured to sense a cardiac signal via the one or more electrodes. The device further includes processing circuitry configured to determine an R-wave of the cardiac signal and determine whether the R-wave is noisy. Based on the R-wave being noisy, the processing circuitry is configured to determine whether the cardiac signal around a determined T-wave is noisy. Based on the cardiac signal around the determined T-wave not being noisy, the processing circuitry is configured to determine a QT interval or a corrected QT interval based on the determined T-wave and the determined R-wave.