Abstract: Systems and methods for detecting cardiac arrhythmia are discussed. A medical-device system includes an ambulatory monitor device and an arrhythmia analysis device communicatively coupled to each other. The ambulatory monitor device can sense a cardiac signal from the patient, and intermittently collect data segments of the cardiac signal in accordance with a data segment collection rate or schedule over a monitoring period. The data segments each has a specific segment duration. The monitor device can transmit the intermittently collected data segments to the arrhythmia analysis device in accordance with a transmission schedule or in response to a trigger event. The arrhythmia analysis device can detect a cardiac arrhythmia from the intermittently collected data segments. The segment duration or the data segment collection rate or schedule may be adjusted based on a performance measure of the arrhythmia detection.

Abstract: Systems and methods for calibrating an orientation of an implantable device in a patient is described. An exemplary system includes a calibration circuit that can receive acceleration information sensed from an implantable medical device (IMD) implanted in a patient, and receive reference acceleration information sensed from a reference device associated with the patient. The acceleration information and the reference acceleration information are acquired when the patient assumes a first posture or in a first position. The calibration circuit determines a spatial relationship between an orientation of the IMD and a reference orientation of the reference device using the received acceleration information and the received reference acceleration information, and calibrate subsequent acceleration information sensed from the IMD using the determined spatial relationship to correct for the orientation of the IMD.

Abstract: Systems and methods for detecting cardiac events in a patient are described herein. An embodiment of a medical system includes a detection circuit configured to detect cardiac events of the patient at different detection settings using physiologic information of the patient and a control circuit to determine a priority for each detected cardiac event based on the detection setting used to detect the respective cardiac event and to prioritize system resources for the detected cardiac event according to the determined priorities, wherein to prioritize system resources comprises to allocate memory space for the detected cardiac events or to prioritize data transmission of the detected cardiac events to an external system based on the determined priority for each respective cardiac event.

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: 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: Some method examples may include pacing a heart with cardiac paces, sensing a physiological signal for use in detecting pace-induced phrenic nerve stimulation, performing a baseline level determination process to identify a baseline level for the sensed physiological signal, and detecting pace-induced phrenic nerve stimulation using the sensed physiological signal and the calculated baseline level. Detecting pace-induced phrenic nerve stimulation may include sampling the sensed physiological signal during each of a plurality of cardiac cycles to provide sampled signals and calculating the baseline level for the physiological signal using the sampled signals. Sampling the sensed physiological signal may include sampling the signal during a time window defined using a pace time with each of the cardiac cycles to avoid cardiac components and phrenic nerve stimulation components in the sampled signal.

Abstract: This document discusses, among other things, systems and methods to receive cardiac electrical information of a subject, detect a premature ventricular contraction (PVC) event in a first detection window using the received cardiac electrical information, determine a count of detected PVC events in the first detection window, remove cardiac electrical information associated with the detected PVC event from the first detection window based on the determined count of detected PVC events, and detect an indication of atrial fibrillation of the subject for the first detection window using remaining cardiac electrical information in the first detection window.

Abstract: Systems and methods for managing medical information storage and transmission are discussed. A data management system may include a receiver circuit to receive information about a physiological event sensed from a patient, and an event prioritizer circuit to assign a priority to the received information. A control circuit may perform data reduction of the received information according to the assigned priority. Data reduction at a higher reduction rate is performed on the received information if a lower priority is assigned than if a higher priority is assigned. The system may include an output circuit to output the received information to a user or a process, or to transmit the received information to an external device, according to the assigned priority.

Abstract: Systems and methods for ambulatory detection of Q wave-to-T wave (QT) interval prolongation are discussed. A medical-device system comprises a controller circuit and a user interface device. The controller circuit includes a long QT syndrome (LQTS) detector that measures a QT interval from a subcutaneous cardiac signal sensed from a patient using implantable electrodes, and detects an indication of QT prolongation using the measured QT time interval and a programmable threshold received as a user input from the user interface. The control circuit can adjust device operation based on the detected indication of QT prolongation. An output unit can generate a programmable alert of the QT prolongation corresponding to the user input of the programmable threshold.

Abstract: Systems and methods for detecting cardiac arrhythmia are discussed. An exemplary medical-device system includes an arrhythmia detector circuit that receives physiologic information, including respiration and heart beat information a patient, and determines whether a respiratory sinus arrhythmia (RSA) is present or absent using the respiration and the heart beat information. An indication of the presence or absence of RSA may be stored in a memory. The arrhythmia detector circuit can detect an AT episode using the indication of RSA.

Abstract: Systems and methods for managing machine-generated alert notifications of medical events detected from one or more patients are described herein. An embodiment of a data management system may receive an adjudication of a medical event episode including an episode characterization. A storage unit stores an association between one or more episode characterizations and corresponding detection algorithms for detecting a medical event having respective episode characterizations. An episode management circuit may detect from a subsequent episode, using the stored association, a medical event having an episode characterization of at least one medical event episode presented for adjudication, and schedule presenting at least a portion of the subsequent episode based on the 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: Systems and methods for monitoring chronic over-pacing (COP) to the heart are discussed herein. In an embodiment, a system includes a receiver circuit to receive information about pacing rates of a plurality of paced heart beats, and a pacing analyzer circuit to generate a pacing rate distribution using pacing rates of the plurality of the paced heart beats. The pacing rate distribution includes a pacing rate histogram. The pacing analyzer circuit may recognize a morphological pattern from the pacing rate distribution, and detect a COP indication using the extracted feature. A programmer circuit adjusts one or more therapy parameters in response to the detected. COP indication.

Abstract: Systems and methods for managing machine-generated alert notifications of medical events detected from one or more patients are described herein. An embodiment of a data management system may receive an adjudication of a medical event episode including an episode characterization. A storage unit stores an association between one or more episode characterizations and corresponding detection algorithms for detecting a medical event having respective episode characterizations. An episode management circuit may detect from a subsequent episode, using the stored association, a medical event having an episode characterization of at least one medical event episode presented for adjudication, and schedule presenting at least a portion of the subsequent episode based on the detection.

Abstract: An example of a system includes an implantable medical device (IMD) for implantation in a patient, where the IMD includes a cardiac pace generator, phrenic nerve stimulation (PS) sensor, a memory, and a controller, and where the controller is operably connected to the cardiac pace generator to generate cardiac paces. The controller is configured to provide a trigger for conducting a PS detection procedure and perform the PS detection procedure in response to the trigger. In performing the PS detection procedure the controller is configured to receive a signal from the sensor, detect PS using the signal from the sensor, and record the PS detection in storage within the IMD.

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: 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: 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: 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.