Abstract: Methods and/or device facilitating and selecting among multiple modes of filtering a cardiac electrical signal, in which one filtering mode includes additional high pass filtering of low frequency signals, relative to the other filtering mode. The selection filtering modes may include comparing sensed signal amplitude to one or more thresholds, using the multiple modes of filtering. In another example, an additional high pass filter is enabled, over and above a default or baseline filtering mode, and the detected cardiac signal is monitored for indications of possible undersensing, and/or for drops in amplitude toward a threshold, and the additional high pass filter may be disabled upon finding of possible undersensing or drop in signal amplitude.

Abstract: Systems and methods for detecting and classifying premature ventricular contractions (PVCs) are discussed. An exemplary system includes a sensor circuit to sense a cardiac signal of a subject, and a processor circuit to detect heartbeats from the cardiac signal and detect a PVC under a first detection mode or a different second detection mode. The first detection mode includes identifying a PVC candidate of a particular type using cardiac intervals or signal amplitudes of the detected heartbeats, and classifying the identified PVC candidate as a PVC singleton or a pattern of multiple consecutive PVCs using signal features including morphology features of the sensed cardiac signal. The second detection mode includes detecting PVC of the particular type using the cardiac intervals or the signal amplitudes of the detected heartbeats. The first detection mode can be transitioned to the second detection mode in response to a mode-switching trigger event.

Abstract: Systems and methods for detecting heart sound information from a subject's head are described. A system embodiment includes a headgear to be worn on the subject's head, and first and second sensors to sense respectively first and second physiologic signals each representing vibration, motion, or displacement conducted through patient body tissue. The sensed physiologic signals contain heart sound information. At least one of the first or the second sensor is included in the headgear, and placed at a head location to sense a physiologic signal indicative of heart sounds. The system includes a processor to generate a composite signal using the sensed first and second physiologic signals. The system may generate a heart sound metric using the composite signal, and detect a cardiac event such as an arrhythmia or worsening heart failure.

Abstract: Systems and methods for detecting an arrhythmic event and storing physiological information associated with the detected arrhythmic event are described. A system may include a first detector to detect an arrhythmic event from a physiological signal sensed from a subject, and generate a confidence indicator indicating a confidence level of the detection of the arrhythmic event. If the confidence indicator indicates a relatively high confidence of arrhythmia detection, the system may provide the detected arrhythmic event to a first process for storing the detected arrhythmic event or generating an alert. If the confidence indicator indicates a relatively low confidence of arrhythmia detection, the system may provide the detected arrhythmic event to at least a second process including confirming or rejecting the detected arrhythmic event.

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 ventricularly implantable medical device that includes a sensing module that is configured to detect an atrial fiducial and identify an atrial contraction based at least on part on the detected atrial fiducial. Control circuitry in the implantable medical device is configured to deliver a ventricular pacing therapy to a patient's heart based at least in part on the identified atrial contraction, and can automatically switch or revert the ventricular pacing therapies on the fly.

Abstract: Systems and methods for managing heart failure are described. The system receives physiological information including a first HS signal corresponding to paced ventricular contractions and a second HS signal corresponding to intrinsic ventricular contractions. The system detects worsening heart failure (WHF) using the received physiological information. A signal analyzer circuit can generate a paced HS metric from the first HS signal and a sensed HS metric from the second HS signal, and determine a concordance indicator between the paced and the sensed HS metrics. In response to the detected WHF, the system can use the concordance indicator to generate a therapy adjustment indicator for adjusting electrostimulation therapy, or a worsening cardiac contractility indicator indicating the detected WHF is attributed to degrading myocardial contractility.

Abstract: Systems and methods for managing heart failure are described. The system receives physiological information including a first HS signal corresponding to paced ventricular contractions and a second HS signal corresponding to intrinsic ventricular contractions. The system detects worsening heart failure (WHF) using the received physiological information. A signal analyzer circuit can generate a paced HS metric from the first HS signal and a sensed HS metric from the second HS signal, and determine a concordance indicator between the paced and the sensed HS metrics. In response to the detected WHF, the system can use the concordance indicator to generate a therapy adjustment indicator for adjusting electrostimulation therapy, or a worsening cardiac contractility indicator indicating the detected WHF is attributed to degrading myocardial contractility.

Abstract: Systems, methods and implantable devices configured to provide cardiac resynchronization therapy and/or bradycardia pacing therapy. A first device located in the heart of the patient is configured to receive a communication from a second device and deliver a pacing therapy in response to or in accordance with the received communication. A second device located elsewhere is configured to determine an atrial event has occurred and communicate to the first device to trigger the pacing therapy. The second device may be configured for sensing the atrial event by the use of vector selection and atrial event windowing, among other enhancements. Exception cases are discussed and handled as well.

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: Methods, systems and devices for providing cardiac resynchronization therapy (CRT) to a patient using a leadless cardiac pacemaker (LCP) and an extracardiac device (ED). The LCP is configured to deliver pacing therapy at a pacing interval. Illustratively, the ED may be configured to analyze the cardiac cycle including a portion preceding the pacing therapy delivery for one or several cardiac cycles, and determine whether an interval from the P-wave to the pace therapy in the cardiac cycle(s) is in a desired range. In an example, if the P-wave to pace interval is outside the desired range, the ED communicates to the LCP to adjust the pacing interval.

Abstract: This document discusses, among other things, systems and methods to generate a first pacing waveform during a first pacing period and a second pacing waveform during a second pacing period, to alternate first and second pacing periods to provide pacing-based hypertension therapy to a heart of a patient to reduce patient blood pressure, to receive information indicative of patient metabolic demand, and to determine an adjusted pacing-based hypertension therapy parameter using the received information indicative of patient metabolic demand, wherein the first pacing waveform has a first atrioventricular (AV) delay and the second pacing waveform has a second AV delay longer than the first AV delay.

Abstract: This document discusses, among other things, systems and methods to determine a response between received cardiac electrical information from a subject, such as a time of a P wave, and received cardiac acceleration information of the subject, such as a time of a first heart sound (S1) or a second heart sound (S2), across a set of stimulation signals provided to the subject at different AVD intervals, and determining one or more cardiac resynchronization therapy (CRT) parameters using an inflection point of the determined response.

Abstract: This document discusses, among other things, systems and methods to determine a response curve between received cardiac electrical information from a subject, such as a time of a P wave, and received cardiac acceleration information of the subject, such as a time of a first heart sound (S1) or a second heart sound (S2), to a set of stimulation signals provided to the subject at different AVD intervals. In certain examples, one or more cardiac resynchronization therapy (CRT) parameters can be determined for the subject using the determined response curve.

Abstract: An implantable medical device (IMD) that includes a housing, a first electrode secured relative to the housing, a second electrode secured relative to the housing, and a gyroscope secured relative to the housing. The IMD may include circuitry in the housing in communication with the first electrode, the second electrode, and the gyroscope. The circuitry may be configured to determine and store a plurality of torsion data measurements, from which a representation of a twist profile may be determined.

Abstract: This document discusses, among other things, systems and methods to receive physiologic information from a patient during different first and second pacing periods having respective, different first and second atrioventricular (AV) delays, determine first and second physiologic parameters using respective received physiologic information from the first and second pacing periods, and adjust the first AV delay using the determined first and second physiologic parameters, wherein the second AV delay is longer than the first AV delay.

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 ventricularly implantable medical device that includes a sensing module that is configured to detect an artifact during ventricular filling and to identify an atrial event based at least on part on the detected artifact. Control circuitry of the implantable medical device is configured to deliver a ventricular pacing therapy to a patient's heart, wherein the ventricular pacing therapy is time dependent, at least in part, on the identified atrial event.

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: Method and system for determining an atrial contraction timing fiducial in a leadless cardiac pacemaker system is disclosed. An electrical cardiac signal associated with an atrial contraction of the patient's heart and a mechanical response to the atrial contraction of a patient's heart are used to determine an atrial contraction timing fiducial. A ventricle pacing pulse may then be generated an A-V delay after the atrial contraction timing fiducial.