Abstract: This document discusses, among other things, systems and methods to adjust arrhythmia detection using physiological information of a patient, including detecting a candidate cardiac event about a threshold, displaying the detected candidate cardiac event to a user, receiving user information about the detected candidate cardiac event, and adjusting an arrhythmia detection threshold based upon the received user information.

Abstract: Systems and methods for managing pain in patient are described. A system may include sensors configured to sense physiological or functional signals, and a pain analyzer to generate signal metrics from the physiological or functional signals. The pain analyzer also generates weight factors corresponding to the signal metrics. The weight factors may indicate the signal metrics reliability in representing an intensity of the pain. The pain analyzer generates a pain score using a plurality of signal metrics and a plurality of weight factors. The pain score may be output to a user or a process. The system may additionally include an electrostimulator to generate and deliver closed-loop pain therapy according to the pain score.

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: An example of a system for providing a patient with pain management includes a pain monitoring circuit. The pain monitoring circuit may include parameter analyzer circuitry and pain score generator circuitry. The parameter analyzer circuitry may be configured to receive and analyze one or more timing parameters and one or more baroreflex parameters allowing for determination of baroreflex sensitivity (BRS) of the patient. The one or more timing parameters are indicative of time intervals during which values of the one or more baroreflex parameters are used to determine the BRS. The pain score generator circuitry may be configured to compute a pain score using an outcome of the analysis. The pain score is a function of the BRS during the time intervals and indicative of a degree of pain of the patient.

Abstract: An apparatus includes a cardiac signal sensing circuit configured to generate a sensed cardiac signal representative of electrical cardiac activity of a subject, a buffer memory and a pause detection circuit. The pause detection circuit is configured to: identify ventricular depolarization in the cardiac signal or the sampled cardiac signal; detect a candidate pause episode using the cardiac signal in which delay in ventricular depolarization exceeds a specified delay threshold; identify noise events in a stored cardiac signal; and discard the cardiac signal of the candidate pause episode when a number of noise events satisfies a specified noise event number threshold, otherwise store the cardiac signal of the candidate pause episode as a bradycardia pause episode.

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 and methods for managing pain in patient are described. A system may include sensors configured to sense physiological or functional signals, and a pain analyzer to generate signal metrics from the physiological or functional signals. The pain analyzer also generates weight factors corresponding to the signal metrics. The weight factors may indicate the signal metrics reliability in representing an intensity of the pain. The pain analyzer generates a pain score using a plurality of signal metrics and a plurality of weight factors. The pain score may be output to a user or a process. The system may additionally include an electrostimulator to generate and deliver closed-loop pain therapy according to the pain score.

Abstract: Systems and methods for detecting atrial tachyarrhythmia are discussed. An exemplary atrial tachyarrhythmia detection system includes an arrhythmia detector circuit configured to receive physiologic information of a patient, generate a morphological similarity metric between the received physiologic information and a sinus rhythm (SR) template representing a morphology of conducted sinus beats during normal SR, and generate a morphological variability metric indicative of a variability in morphology between heart beats in the received physiologic information. The arrhythmia detector circuit may detect an atrial tachyarrhythmia episode the morphological similarity and morphological variability metrics.

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: Systems and methods for multi-site cardiac stimulation are disclosed. The system includes an electrostimulation circuit to deliver electrostimulation to one or more candidate sites of at least one heart chamber. The system may sense a physiological signal including during electrostimulation of the heart, use the physiological signal to determine a first stimulation vector for electrostimulation at a first left ventricular (LV) site and a second stimulation vector for electrostimulation at a different second LV site, and determine a therapy mode including a first chronological order and a first timing offset between stimulations delivered according to the first and second stimulation vectors. The electrostimulation circuit may deliver electrostimulation to the heart in accordance with the first and second stimulation vectors and the therapy mode.

Abstract: An apparatus comprises a cardiac signal sensing circuit configured to sense a plurality of intrinsic cardiac signals using a plurality of cardiac pacing sites, a heart sound sensing circuit, a stimulus circuit configured to provide an electrical cardiac pacing stimulus to the plurality of pacing sites, and a control circuit electrically coupled to the cardiac signal sensing circuit and the stimulus circuit. The control circuit includes a pacing site locating circuit configured to generate an indication of a preferred pacing site as one of a) a subset of the respective cardiac pacing sites selected using the intrinsic ventricular activation time interval value, from which subset the preferred pacing site is selected using the heart sound characteristic value; or b) a subset of the respective cardiac pacing sites selected using the heart sound characteristic value, from which subset the preferred pacing site is selected using the ventricular activation time interval value.

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: 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.