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.

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 using one or more filters. Model reduction schemes such as independent component analysis can additionally or alternatively be employed to extract the cardiac signal. 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. The determined cardiac features can additionally be used to adjust parameters of the stimulation that is provided by the neurostimulator.

Abstract: Systems and methods to determine P wave oversensing (PWOS) are disclosed, including identifying cardiac signal features in received cardiac electrical information, determining a first indication of PWOS using a pattern of identified cardiac signal features, and in response to the determined first indication of PWOS, determining a second indication of PWOS using a morphology of the received cardiac electrical information.

Abstract: Regulating cardiac activity may include pacing the patient's heart at a starting pacing rate and instigating an intrinsic heart beat search algorithm that includes pacing at a reduced rate for a period of time and capturing electrical signals representative of cardiac electrical activity while pacing at the reduced rate in order to determine a presence or absence of intrinsic heart beats. If intrinsic heart beats are not detected, the heart may be paced at a further reduced rate for a period of time. If intrinsic beats are detected, the heart may be paced again at the starting pacing rate. This may continue until intrinsic heart beats are detected or until a lower search rate limit is reached. Diagnostic data may be collected at each stage and transmitted to a display device for analysis by a physician or the like.

Abstract: Systems and methods for classifying a cardiac arrhythmia are discussed. An exemplary system includes a correlator circuit to generate autocorrelation sequences using information of cardiac activity of a subject, including signal segments taken from a cardiac signal at respective elapsed time with respect to reference time. The correlator circuit can generate a correlation image using the autocorrelation sequences. The correlation image may be constructed by stacking the autocorrelation sequences according to the elapsed time of signal segments. An arrhythmia classifier circuit can classify the cardiac activity of the subject as one of arrhythmia types using the correlation image.

Abstract: A system for lead integrity monitoring includes an implantable medical device (IMD) having a housing enclosing a control circuit; and a lead, having a first sensor. The lead is coupled to the housing and electrically coupled to the control circuit. The system also includes at least one processing device configured to identify a first lead failure alert based on a first set of information; obtain a second set of information generated by a second sensor; perform an evaluation of the first set of information in the context of the second set of information; and confirm or cancel the first lead failure alert based on the evaluation.

Abstract: This document discusses, among other things, systems and methods to detect an initial arrhythmia event indication and, after a threshold amount of detection window intervals detecting the initial arrhythmia event indication, adjust a set of arrhythmia parameters or at least one of a respective set of parameter thresholds to increase sensitivity of an extended arrhythmia event indication detection.

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: 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: 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: 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. 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.