Abstract: This document discusses, among other things, systems and methods to receive cardiac electrical information and premature ventricular contraction (PVC) information of a subject, detect atrial fibrillation (AF) of the subject using the received cardiac electrical information, and adjust AF detection using the received PVC information.

Abstract: An example of a system may include a sensing circuit and an atrial fibrillation (AF) detection circuit. The sensing circuit may be configured to sense a cardiac signal indicative of atrial and ventricular depolarizations. The AF detection circuit may be configured to detect AF using the cardiac signal and may include a detector and a detection enhancer. The detector may be configured to detect the ventricular depolarizations using the cardiac signal, to measure ventricular intervals each between two successively detected ventricular depolarizations, and to detect the AF using the ventricular intervals. The detection enhancer may include a respiratory sinus arrhythmia (RSA) detector configured to detect RSA using the cardiac signal and may be configured to verify each detection of the AF based on whether the RSA is detected.

Abstract: This document discusses, among other things, apparatus, systems, and methods to determine a first atrial fibrillation (AF) indication using received information about a heart over a first period, to cluster depolarization information about the heart over the first period, and to discriminate between an atrial fibrillation (AF) event and a non-AF event in the first period using the determined first AF indication the clustered depolarization information.

Abstract: An apparatus includes a sensing circuit configured to generate a sensed physiological signal that includes physiological information of a subject, a detection circuit, and a control circuit. The detection circuit detects a physiological condition of a subject using the physiological signal. The control circuit stores sampled values of a segment of the physiological signal in temporary memory storage; and stores the sampled values in non-temporary storage in response to receiving an indication of continued detection of the physiological condition.

Abstract: Systems and methods for pacing cardiac conductive tissue are described. An exemplary system includes an electrostimulation circuit that may generate HBP pulses to stimulate patient physiologic conduction pathway, such as a His bundle or a bundle branch. The system includes an arrhythmia detector to detect an atrial tachyarrhythmia (AT) with intermittent ventricular conduction. A control circuit may sense ventricular activation and, in response to the detected AT indication, determine or update a His-bundle pacing (HBP) configuration. The HBP may be recursively updated on a beat-by-beat basis using the sensed ventricular activation. The electrostimulation circuit may deliver HBP according to the determined or adjusted HBP configuration to regularize ventricular rate during AT.

Abstract: Systems and methods for detecting cardiac arrhythmias such as atrial tachyarrhythmia (AT) are discussed. An exemplary system includes a ventricular beat analyzer circuit to detect ventricular beats and assess ventricular activity, such as to evaluate a ventricular rate stability. The system includes an arrhythmia detector circuit to detect respective AT indications in distinct time periods using portions of received physiologic information during the distinct time periods. A control circuit can monitor the ventricular beats on a beat-by-beat basis, in response to the detected ventricular beats satisfying an instability condition, trigger AT detections during the distinct time periods and withhold AT detection in a subsequent time period if no AT is detected in the present time period. An AT characteristic may be generated using the detected AT indications. A therapy may be delivered in accordance with the AT characteristic.

Abstract: Systems and methods for detecting cardiac arrhythmia are discussed. An exemplary arrhythmia detection system can receive physiologic information of the patient, measure a first signal metric using a first portion of the received physiologic information, and determine an arrhythmia detection duration using a comparison between the measured first signal metric and a reference signal metric value. The system includes an arrhythmia detector to detect an AT episode using a second portion of the physiologic information corresponding to the determined arrhythmia detection duration.

Abstract: Systems and methods for dynamically controlling HBP delivery based on patient AV conduction status are disclosed. An exemplary medical system includes an electrostimulation circuit to generate HBP pulses to stimulate a His bundle or a bundle branch of the heart. An AV conduction monitor circuit continuously or periodically assesses AV conduction status, and detects an indication of presence or absence of AV conduction abnormality. If an AV conduction abnormality is indicated, a control circuit may control the electrostimulation circuit to deliver the HBP pulses. Ventricular backup pacing may be delivered if HBP fails to capture and elicit ventricular activation. When the AV conduction become normal, the control circuit may withhold HBP delivery and promote patient intrinsic ventricular activation.

Abstract: Systems and methods for pacing cardiac conductive tissue are described. In an embodiment, a medical system includes an electrostimulation circuit to generate pacing pulses to stimulate a His bundle or a bunch branch. A sensing circuit senses a far-field ventricular activation, determines a cardiac synchrony indicator using the far-field ventricular activation in response to His bundle or bundle branch pacing, and verifies His-bundle capture status using the determined cardiac synchrony indicator. The system can determine a pacing threshold using the capture status under different stimulation strength values. The electrostimulation circuit can deliver stimulation pulses in accordance with the determined pacing threshold.

Abstract: A system for monitoring a subject for an arrhythmia includes an external monitoring device (EMD) configured to be disposed outside of a subject's body. The EMD includes a first communication component configured to receive, from a medical device, a first physiological parameter signal and an indication of a detected trigger event associated with a first portion of the first physiological parameter signal. The trigger event is indicative of a potential arrhythmia. The EMD also includes an analysis component configured to (1) identify a second portion of the first physiological parameter signal, where the second portion satisfies a discard criterion, (2) discard the second portion, and (3) perform an arrhythmia confirmation evaluation using a third portion of the first physiological parameter signal.

Abstract: An apparatus includes a sensing circuit configured to generate a sensed physiological signal representative of cardiac activity of a subject, an arrhythmia detection circuit, a control circuit, and a memory. The arrhythmia detection circuit detects an episode of atrial fibrillation (AF) in the sensed cardiac signal using a first AF detection criterion, and detects the episode of AF using a second AF detection criterion. The first AF detection criterion has greater sensitivity to AF detection than the second AF detection criterion, and the second AF detection criterion has greater specificity to AF detection than the first AF detection criterion. The control circuit initiates storing of sampled values of a segment of the cardiac signal that includes the episode of AF when the episode of AF is detected by both the first AF detection criterion and the second AF detection criterion.

Abstract: Systems, devices, and methods for monitoring and assessing immunotherapy toxicity are discussed. An exemplary system receives physiologic information from a patient using an ambulatory medical device. In response to an immunotherapy such as CAR T-cell therapy, the system determines a toxicity indication using the received physiologic information. A therapy can be initiated or adjusted using the toxicity indication.

Abstract: Systems and methods for presenting physiologic data to a user are discussed. An exemplary system includes a presentation control circuit configured to generate signal metrics from data subsets of a physiologic signal corresponding to a device-detected presence of a physiologic event. The signal metrics represent characteristics of the physiologic event. The presentation control circuit may determine, from the plurality of data subsets, a target subset of clinical significance, which has the corresponding signal metric satisfying a specific condition. The presentation control circuit may present the recognized target subset over other subsets of the physiologic data. A user may adjudicate the device detection of the physiologic event or adjust device parameters.

Abstract: An apparatus includes a sensing circuit configured to generate a sensed physiological signal representative of cardiac activity of a subject, and an arrhythmia detection circuit. The arrhythmia detection circuit is configured to monitor information corresponding to ventricular depolarization (V-V) intervals using the sensed physiological signal; determine a V-V interval distribution; determine a heart rate density index (HRDI) as a portion of samples of the V-V interval distribution corresponding to a V-V interval occurring most often in the distribution; and generate an indication of atrial fibrillation (AF) using the HRDI.

Abstract: Systems and methods for detecting physiologic events in a patient are described herein. An embodiment of a medical system includes a memory circuit to store physiologic event episodes detected and recorded by a medical device. The system includes a control circuit to analyze the stored physiologic event episodes, and determine a presence of a target cardiac event under a plurality of detection settings. Using the determined presence of the target cardiac event from the stored physiologic event episodes, and user adjudication of the stored event episodes, the control circuit may select, from the plurality of detection settings, a detection setting to detect a subsequent target cardiac event. The control circuit may also prioritize the physiologic event episodes for storage in the memory circuit.

Abstract: Systems and methods for pacing cardiac conductive tissue are described. An embodiment of a medical system includes an electrostimulation circuit to generate His-bundle pacing (HBP) pulses to stimulate a His bundle, and a cardiac event detector to detect a His-bundle activity within a time window following an atrial activity. The cardiac event detector may use a cross-chamber blanking, or an adjustable His-bundle sensing threshold, to avoid or reduce over-sensing of far-field atrial activity and inappropriate inhibition of HBP therapy. The electrostimulation circuit may deliver HBP in the presence of the His-bundle activity. The system may further recognize the detected His-bundle activity as either a FFPW or a valid inhibitory event, and deliver or withhold HBP therapy based on the recognition of the His-bundle activity.

Abstract: An example of a system may include a sensing circuit to sense a cardiac signal indicative of atrial and ventricular depolarizations and an atrial fibrillation (AF) detection circuit to detect AF. The AF detection circuit may include a detector and a detection enhancer. The detector may be configured to detect the ventricular depolarizations using the cardiac signal, measure ventricular intervals, and detect AF using the ventricular intervals. The detection enhancer may be configured to generate atrial detection windows each being a time interval prior to each of the detected ventricular depolarizations, compute an atrial activity score using a rolling average of portions of the cardiac signal within the atrial detection windows, and verify the detection of the AF using the atrial activity score and an atrial activity threshold. The atrial activity score is a measure of consistency between a relationship between the atrial depolarizations and the ventricular depolarizations.

Abstract: Systems and methods for ambulatory detection of medical events such as cardiac arrhythmia are described herein. An embodiment of an arrhythmia detection system may include a detection criterion circuit that determines a patient-specific detection criterion using a baseline cardiac characteristic when the patient is free of cardiac arrhythmias. The detection criterion circuit generates a patient-specific threshold of a signal metric by adjusting a population-based threshold of the signal metric, where the manner and the amount of adjustment is based on information about patient baseline cardiac characteristic. The arrhythmia detection system detects an arrhythmia episode using a physiologic signal sensed from the patient and the patient-specific arrhythmia detection threshold.

Abstract: A device for the active fixation of an implantable medical lead includes a housing, a tine assembly, an electrode, and a rotatable shaft. The housing includes a proximal end for connecting to the lead and a distal end opposite the proximal end. The housing defines a housing lumen extending between the proximal end and a recess adjacent to the distal end. The tine assembly is disposed within the housing lumen and includes at least one tine configured to self-bias from a linear configuration within the housing to a curved configuration outside of the housing. The electrode assembly is disposed at the distal end of the housing and includes a plurality of electrodes. The rotatable shaft extends through the housing lumen and is configured to engage the tine assembly such that rotation of the shaft transitions the at least one tine between the linear configuration and the curved configuration.

Abstract: An arrhythmia classification system receives cardiac data from an implantable medical device, performs automatic adjudication of each cardiac arrhythmia episode indicated by the cardiac data, and generates episode data representative of information associated with the episode. The episode data include at least an episode classification resulting from the automatic adjudication of the episode and a confidence level in the episode classification. In one embodiment, the episode data further include key features rationalizing the automatic adjudication of the episode.