Abstract: Systems, methods, and interfaces are described herein for assisting a user in noninvasive evaluation of patients for cardiac therapy and noninvasive evaluation of cardiac therapy being delivered. The systems, methods, and interfaces may provide graphical representations of cardiac electrical activation times about one or more portions of human anatomy and one or more cardiac health metrics.

Abstract: The present disclosure relates to cardiac evoked response detection and, more particularly, reducing polarization effects in order to detect an evoked response following delivery of a stimulation pulse. An implantable medical device (IMD) is configured to deliver a ventricular pacing pulse. A signal is sensed in response to the ventricular pacing stimulus. A window is placed over the sensed signal to obtain a set of data from the signal after a paced event. The set of data extracted from the sensed signal comprises a maximum amplitude, a maximum time associated with the maximum amplitude, a minimum amplitude, and a minimum time associated with the minimum amplitude. Responsive to processing the extracted data, the window is delayed to avoid polarization effects. A determination is then made as to whether the ventricular pacing stimulus is capturing the paced ventricle in response to determining whether the maximum time is greater than the minimum time.

Abstract: A medical device system for controlling ventricular pacing therapy during cardiac resynchronization therapy that includes a sensing device to sense a cardiac signal and emit a trigger signal in response to the sensed cardiac signal, a therapy delivery device to deliver the ventricular pacing in response to the emitted trigger signal, and a processor configured to identify a fiducial point of the cardiac signal sensed in real-time, set a window comprising a start point positioned a first distance prior to the fiducial point and an endpoint positioned a second distance less than the first distance subsequent to the fiducial point, determine a signal characteristic of the cardiac signal within the window, determine whether a P-wave is detected in response to the signal characteristic, determine whether an atrio-ventricular interval timer has expired, and emit a trigger signal to deliver the ventricular pacing timed off of the local maximum in response to the P-wave being detected and not timed off of the local m

Abstract: Techniques for evaluating cardiac electrical dyssynchrony are described. In some examples, an activation time is determined for each of a plurality of torso-surface potential signals. The dispersion or sequence of these activation times may be analyzed or presented to provide variety of indications of the electrical dyssynchrony of the heart of the patient. In some examples, the locations of the electrodes of the set of electrodes, and thus the locations at which the torso-surface potential signals were sensed, may be projected on the surface of a model torso that includes a model heart. The inverse problem of electrocardiography may be solved to determine electrical activation times for regions of the model heart based on the torso-surface potential signals sensed from the patient.

Abstract: Techniques for evaluating cardiac electrical dyssynchrony are described. In some examples, an activation time is determined for each of a plurality of torso-surface potential signals. The dispersion or sequence of these activation times may be analyzed or presented to provide variety of indications of the electrical dyssynchrony of the heart of the patient. In some examples, the locations of the electrodes of the set of electrodes, and thus the locations at which the torso-surface potential signals were sensed, may be projected on the surface of a model torso that includes a model heart. The inverse problem of electrocardiography may be solved to determine electrical activation times for regions of the model heart based on the torso-surface potential signals sensed from the patient.

Abstract: Methods and/or devices may be configured to track effectiveness of pacing therapy by monitoring activation times over time, e.g., between pacing stimulus and electrical activity resulting from the pacing stimulus. Generally, the methods and/or devices may determine whether the delivered pacing therapy was effective based on the measured activation times.

Abstract: Methods and/or devices may be configured to monitor ventricular activation times and modify an atrioventricular delay (AV delay) based on the monitored ventricular activation times. Further, the methods and/or devices may determine whether the AV delay should be modified based on the measured activation times before modifying the AV delay.

Abstract: Systems, methods, and interfaces are described herein for identification of effective electrodes to be used in sensing and/or therapy. Two or more portions of a signal monitored using an electrode may be compared to determine whether the electrode is effective. The two or more portions may correspond to the same portion or window of a cardiac cycle. Further, signals from a first electrode and from a second electrode located proximate the first electrode may be compared to determine whether one or both of the electrodes are effective.

Abstract: Systems, methods, and interfaces are described herein for identification of effective electrodes to be used in sensing and/or therapy. Two or more portions of a signal monitored using an electrode may be compared to determine whether the electrode is effective. The two or more portions may correspond to the same portion or window of a cardiac cycle. Further, signals from a first electrode and from a second electrode located proximate the first electrode may be compared to determine whether one or both of the electrodes are effective.

Abstract: An implantable medical device system operates in an atrial synchronized ventricular pacing mode and switches to an atrial-asynchronous pacing mode when pacing mode switching criteria are met. A control circuit of the system detects a cycle length change between two atrial cycle lengths determined from a cardiac signal that includes far-field atrial events. If the cycle length change is greater than a change, threshold the control circuit determines if the pacing mode switching criteria are satisfied subsequent to detecting the cycle length change.

Abstract: Systems, methods, and interfaces are described herein for assisting in noninvasive location selection for an implantable electrode for use in cardiac therapy. Mechanical motion information and surrogate electrical activation times may be used to identify one or more candidate site regions.

Abstract: A system and associated method for determining whether a signal is ambiguous, wherein the system includes a plurality of electrodes configured to be located proximate tissue of a patient. A display apparatus thereof includes a graphical user interface configured to present information to a user. A computing apparatus thereof is configured to determine maximums for beats of signals from the electrodes.

Abstract: A medical device system for controlling ventricular pacing therapy during cardiac resynchronization therapy that includes a sensing device to sense a cardiac signal and emit a trigger signal in response to the sensed cardiac signal, a therapy delivery device to deliver the ventricular pacing in response to the emitted trigger signal, and a processor configured to identify a fiducial point of the cardiac signal sensed in real-time, set a window comprising a start point positioned a first distance prior to the fiducial point and an endpoint positioned a second distance less than the first distance subsequent to the fiducial point, determine a signal characteristic of the cardiac signal within the window, determine whether a P-wave is detected in response to the signal characteristic, determine whether an atrio-ventricular interval timer has expired, and emit a trigger signal to deliver the ventricular pacing timed off of the local maximum in response to the P-wave being detected and not timed off of the local m

Abstract: Methods and/or devices may be configured to monitor ventricular activation times and modify an atrioventricular delay (AV delay) based on the monitored ventricular activation times. Further, the methods and/or devices may determine whether the AV delay should be modified based on the measured activation times before modifying the AV delay.

Abstract: Systems, methods, and interfaces are described herein for noninvasively determining an optimal coronary sinus branch to cannulate for a medical electrical lead. One exemplary method involves applying an electrode apparatus having a plurality of electrodes to a torso of a patient. One of a right ventricular (RV) lead is introduced to a right ventricle or a right atrial (RA) lead is introduced to a right atrium. Noninvasively ultrasonic energy is introduced to a target tissue selected from a set of target tissues. In response to delivering ultrasonic energy to the cardiac tissue, a processing unit receives a torso-surface potential signal from each of a plurality of electrodes distributed on a torso of a patient for the target tissue. Signals are sensed from one of the RA lead and the RV lead in response to delivering ultrasonic energy. For at least a subset of the plurality of electrodes, calculating, with the processing unit, a torso-surface activation time based on the signal sensed from the electrode.

Abstract: A system and associated method is disclosed for determining whether a signal is ambiguous. The system comprises a plurality of electrodes configured to be located proximate tissue of a patient. A display apparatus comprises a graphical user interface configured to present information to a user. A computing apparatus is coupled to the electrode apparatus. The computing apparatus is configured to calculate a first derivative of a signal acquired from the electrodes, determine a first minimum from the first derivative, determine a second minimum from the second derivative and a second index within a window, calculate a ratio of the first and second derivatives, calculate a difference between a first and second index. In response to determining the ratio and the difference between the first and second index, the display apparatus displays whether the signal is ambiguous.

Abstract: Systems, methods, and graphical user interfaces are described herein for non-invasively detecting phrenic nerve stimulation during cardiac pacing therapy. Phrenic nerve stimulation information may be generated for one or more electrical pacing vectors at one or more power configurations. The phrenic nerve stimulation information may be displayed to a user for use in configuring and/or evaluating cardiac pacing therapy.

Abstract: An intracardiac ventricular pacemaker is configured to detect an atrial mechanical event from a motion sensor signal received by an atrial event detector circuit of the pacemaker. The motion sensor signal is responsive the motion of blood flowing in the ventricle. A pacing pulse is scheduled at an expiration of a pacing interval set by a pace timing circuit in response to detecting the atrial mechanical event. An atrial-synchronized ventricular pacing pulse is delivered upon expiration of the pacing interval.

Abstract: The present disclosure pertains to cardiac pacing methods and systems, and, more particularly, to cardiac resynchronization therapy (CRT). In particular, the present disclosure pertains to determining whether a patient is experiencing atrial fibrillation (AF). If the patient is experiencing AF, the efficacy of CRT is determined. A signal is sensed in response to a ventricular pacing stimulus. Through signal processing, a number of features are parsed from the signal and a determination is made as to whether the ventricular pacing stimulus evoked a response from the ventricle.

Abstract: Systems and methods are described herein for assisting a user in identification of interventricular (V-V) delay for cardiac therapy. The systems and methods may monitor electrical activity of a patient using external electrode apparatus to provide electrical heterogeneity information for a plurality of different V-V intervals and may identify a V-V interval based on the electrical heterogeneity information.