Abstract: An apparatus comprises an arrhythmia detection circuit configured to: receive a cardiac signal representative of cardiac activity of a subject; apply a first arrhythmia detection criteria to the received cardiac signal; apply, in response to the applied first arrhythmia detection criteria producing a positive indication of arrhythmia, a second arrhythmia detection criteria to the received cardiac signal, wherein the second arrhythmia detection criteria is more specific to detection of arrhythmia than the first detection criteria; detect, in response to the applied first and second arrhythmia detection criteria, a sensing event indicating one or both of the first and second arrhythmia detection criteria are susceptible to false indications of arrhythmia; and adjust, in response to a detected sensing event, sensitivity or specificity of one or both of the first and second arrhythmia detection criteria.

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: Systems and methods for managing cardiac arrhythmias are discussed. A data management system receives a first detection algorithm including a detection criterion for detecting a cardiac arrhythmia. An arrhythmia detector detects arrhythmia episodes from a physiologic signal using a second detection algorithm that is different from and has a higher sensitivity for detecting the cardiac arrhythmia than the first detection algorithm. The arrhythmia detector assigns a detection indicator to each of the detected arrhythmia episodes. The detection indicator indicates a likelihood that the detected arrhythmia episode satisfies the detection criterion of the first detection algorithm. The system prioritizes the detected arrhythmia episodes according to the assigned detection indicators, and outputs the arrhythmia episodes to a user or a process according to the episode prioritization.

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: 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. A medical-device system includes an arrhythmia detector circuit and an event prioritizer circuit. The arrhythmia detector circuit can detect an atrial activation event from a cardiac electrical signal sensed from the patient, and determine an atrial fibrillation (AF) confidence indicator based on a signal characteristic of the atrial activation event. The event prioritizer circuit can generate an event priority for the AF event based on the AF confidence indicator. Multiple AF events may be prioritized in a specific order and presented to a user or a process.

Abstract: Described herein are systems and methods for classifying clinical episodes in order to more accurately generate alerts for those episodes that warrant them. In some embodiments, alerts are only generated for those episodes that are new or different from previous episodes, where the previous episodes have been found to be not significant enough to warrant an alert.

Abstract: New and alternative approaches to the monitoring of cardiac signal quality for external and/or implantable cardiac devices. In one example, signal quality is monitored continuously or in response to a triggering event or condition and, upon identification of a reduction in signal quality, a device may reconfigure its sensing state. In another example, one or more trends of signal quality are monitored by a device, either continuously or in response to a triggering event or condition, and sensing reconfiguration may be performed in response to identified trends and events. In yet another example, a device may use a looping data capture mode to track sensing data in multiple vectors while primarily relying on less than all sensing vectors to make decisions and, in response to a triggering event or condition, the looped data can be analyzed automatically, without waiting for additional data capture to reconfigure sensing upon identification of the triggering event or condition.

Abstract: A medical device system has a medical device interface configured to download data from an implanted medical device. Memory stores electrode location identification rules and display definitions. Each of the display definitions correspond to possible electrode placement locations of the implanted medical device. Processing circuitry is configured to compare the downloaded data from the implanted medical device to the electrode location identification rules to identify one or more actual electrode placement locations of the possible electrode placement locations of the implanted medical device. A user output interface is in communication with the processing circuitry. The processing circuitry is configured to cause the output to display the one or more actual electrode placement locations.

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: 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: 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 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 medical device system has a medical device interface configured to download data from an implanted medical device. Memory stores electrode location identification rules and display definitions. Each of the display definitions correspond to possible electrode placement locations of the implanted medical device. Processing circuitry is configured to compare the downloaded data from the implanted medical device to the electrode location identification rules to identify one or more actual electrode placement locations of the possible electrode placement locations of the implanted medical device. A user output interface is in communication with the processing circuitry. The processing circuitry is configured to cause the output to display the one or more actual electrode placement locations.

Abstract: Systems and methods for detecting slow and persistent rhythms, such as indicative of ventricular response to atrial tachyarrhythmia (AT), are described herein. An arrhythmia detection system monitors patient ventricular heart rate, and identifies slow heart beats with corresponding heart rates falling below a rate threshold during a detection period. The system identifies one or more sustained slow beat (SSB) sequences each including two or more slow heart beats. The system determines a first prevalence indicator of the identified slow heart beats, and a second prevalence indicator of the identified SSB sequences during the detection period. An arrhythmia detector circuit detects a slow and persistent rhythm using the first and second prevalence indicators.

Abstract: Systems and methods for managing machine-generated medical events detected from one or more patients are described herein. A medical event management system includes an event analyzer circuit to detect a medical event using physiological data from a patient-triggered episode acquired from a medical device. The event analyzer circuit determines a confidence score of the medical event detection, and generates an alignment indicator indicating a degree of concordance between the detected medical event and the information about the patient-triggered episode. The system assigns priority information to the patient-triggered episode using the generated alignment indicator and the confidence score of the detection. An output circuit can output the received physiological information to a user or a process according to the assigned priority information.

Abstract: Systems and methods to determine an indication of patient dehydration are disclosed, including receiving first and second physiologic information of a patient, the first physiologic information including heart sound information of the patient and the second physiologic information different than the first physiologic information, and determining the indication of patient dehydration using the received first and second physiologic information.

Abstract: Atrial fibrillation information can be determined from ventricular information or a ventricular location, such as using ventricular rate variability. An ambulatory medical device can receive indications of pairs of first and second ventricular rate changes of three temporally adjacent ventricular heart beats. A first count of instances of the pairs meeting a combined rate change magnitude characteristic and a second count of instances of the pairs in which both of the first and second ventricular rate changes are negative can be used to provide atrial fibrillation information.

Abstract: Systems and methods for pacing cardiac conductive tissue are described. A medical system includes an electrostimulation circuit to generate His-bundle pacing (HBP) pulses. A sensing circuit senses a physiologic signal, and detect a local His-bundle activation discrete from a pacing artifact of the HBP pulse. A control circuit verifies capture status in response to the HBP pulses. Based on the capture status, the control circuit determines one or more pacing thresholds including a selective HBP threshold representing a threshold strength to capture only the His bundle but not the local myocardium, and a non-selective HBP threshold representing a threshold strength to capture both the His bundle and the local myocardium. The electrostimulation circuit may deliver HBP pulses based on the selective and non-selective HBP thresholds.

Abstract: A system and method for extracting a cardiac signal from a spinal signal include measuring a spinal signal at one or more electrodes that are connected to a neurostimulator and implanted within a patient's spinal canal and processing the spinal signal to extract the cardiac signal, which includes features that are representative of the patient's cardiac activity. Processing the spinal signal to extract the cardiac signal can include filtering the spinal signal, or use of model reduction schemes such as independent component analysis. The extracted cardiac signal can include a number of features that correspond to an electrocardiogram and can be used to determine the patient's heart rate and/or to detect a cardiac anomaly. Cardiac features that are determined from the cardiac signal can additionally be used to adjust parameters of the stimulation that is provided by the neurostimulator.