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: This document discusses, among other things, systems and methods to adjust arrhythmia detection using physiological information of a patient, including detecting a candidate cardiac event about a threshold, displaying the detected candidate cardiac event to a user, receiving user information about the detected candidate cardiac event, and adjusting an arrhythmia detection threshold based upon the received user information.

Abstract: An apparatus includes a cardiac signal sensing circuit configured to generate a sensed cardiac signal representative of electrical cardiac activity of a subject, a buffer memory and a pause detection circuit. The pause detection circuit is configured to: identify ventricular depolarization in the cardiac signal or the sampled cardiac signal; detect a candidate pause episode using the cardiac signal in which delay in ventricular depolarization exceeds a specified delay threshold; identify noise events in a stored cardiac signal; and discard the cardiac signal of the candidate pause episode when a number of noise events satisfies a specified noise event number threshold, otherwise store the cardiac signal of the candidate pause episode as a bradycardia pause episode.

Abstract: Systems and methods for presenting physiologic data to a user are discussed. An exemplary system includes a presentation control circuit configured to generate signal metrics from data subsets of a physiologic signal corresponding to a device-detected presence of a physiologic event. The signal metrics represent characteristics of the physiologic event. The presentation control circuit may determine, from the plurality of data subsets, a target subset of clinical significance, which has the corresponding signal metric satisfying a specific condition. The presentation control circuit may present the recognized target subset over other subsets of the physiologic data. A user may adjudicate the device detection of the physiologic event or adjust device parameters.

Abstract: This document discusses, among other things, systems and methods to adjust arrhythmia detection using physiological information of a patient, including detecting a candidate cardiac event about a threshold, displaying the detected candidate cardiac event to a user, receiving user information about the detected candidate cardiac event, and adjusting an arrhythmia detection threshold based upon the received user information.

Abstract: An apparatus includes a cardiac signal sensing circuit configured to generate a sensed cardiac signal representative of electrical cardiac activity of a subject, a buffer memory and a pause detection circuit. The pause detection circuit is configured to: identify ventricular depolarization in the cardiac signal or the sampled cardiac signal; detect a candidate pause episode using the cardiac signal in which delay in ventricular depolarization exceeds a specified delay threshold; identify noise events in a stored cardiac signal; and discard the cardiac signal of the candidate pause episode when a number of noise events satisfies a specified noise event number threshold, otherwise store the cardiac signal of the candidate pause episode as a bradycardia pause episode.

Abstract: Methods and systems for performing capture threshold tests are described. During an initialization procedure a capture detection interval and capture detection threshold are determined based on peak values of cardiac signals sensed following the supracapture threshold initialization pulses. Following initialization, a plurality of pacing pulses to the atrium are delivered and the peak values of the cardiac signals sensed following each of the plurality of pacing pulses are determined. The peak values are compared to the pacing artifact threshold and the capture detection threshold. A timing of each of the peak values is compared to the capture detection interval. For each pacing pulse, discrimination between a captured response, a noncaptured response, and a fusion response is based on the peak value and timing comparisons.

Abstract: Methods and systems for performing capture threshold tests are described. During an initialization procedure a capture detection interval and capture detection threshold are determined based on peak values of cardiac signals sensed following the supracapture threshold initialization pulses. Following initialization, a plurality of pacing pulses to the atrium are delivered and the peak values of the cardiac signals sensed following each of the plurality of pacing pulses are determined. The peak values are compared to the pacing artifact threshold and the capture detection threshold. A timing of each of the peak values is compared to the capture detection interval. For each pacing pulse, discrimination between a captured response, a noncaptured response, and a fusion response is based on the peak value and timing comparisons.

Abstract: A system and method for performing off-line analysis of cardiac electrogram data, comprising: retrieving an electrogram from a memory location; identifying a first-channel group of candidate beats from at least a first channel of the electrogram; and identifying a second-channel group of candidate beats from at least a second channel of an electrogram. For each first-channel beat candidate near a second-channel beat candidate, the amplitude of the first-channel beat candidate is compared with the amplitude of a previous beat and the amplitude of a next beat on the first electrogram channel, and first-channel beat candidates that are outside of a first pre-determined range from either the previous or next beat are removed. Then first-channel beat candidates that are outside of a second pre-determined range from either the previous or next beat candidate are removed.

Abstract: A system and method for performing independent, off-line evaluation of event sensing for collected electrograms, comprising: sensing an electrogram using an implantable medical device (IMD); determining locations of heart beats on at least one channel of the electrogram using a multi-pass process, resulting in a group of multi-pass beat locations; storing the electrogram and device-identified beat locations in a memory location; and retrieving the electrogram and device-identified beat locations from the memory location. The multi-pass process determines locations of heart beats on at least a first channel of the electrogram. The device-identified group of beat locations are then compared to the multi-pass group of beat locations identified using the multi-pass method. Based on the comparing step, oversensing of beats, undersensing of beats, or noise from the device can be detected.

Abstract: Methods and systems are directed to selecting from a variety of capture verification modes. A plurality of capture verification modes, including a beat by beat capture detection mode and a capture threshold testing mode without intervening beat by beat capture detection is provided. An efficacy of at least one of the capture verification modes is evaluated, and based on the evaluation, a capture verification mode is selected.

Abstract: Atrial capture threshold testing is performed in accordance with an atrial capture threshold testing schedule. Monitoring for retrograde P-waves occurs at least during times other than times during which scheduled atrial capture threshold testing is performed. In response to detecting a retrograde P-wave indicative of sub-threshold atrial pacing during monitoring, an unscheduled atrial capture threshold test is performed and pacing of the atrium is adjusted based on the unscheduled atrial capture threshold test.

Abstract: Methods and systems for performing capture threshold tests are described. During an initialization procedure a capture detection interval and capture detection threshold are determined based on peak values of cardiac signals sensed following the supracapture threshold initialization pulses. Following initialization, a plurality of pacing pulses to the atrium are delivered and the peak values of the cardiac signals sensed following each of the plurality of pacing pulses are determined. The peak values are compared to the pacing artifact threshold and the capture detection threshold. A timing of each of the peak values is compared to the capture detection interval. For each pacing pulse, discrimination between a captured response, a noncaptured response, and a fusion response is based on the peak value and timing comparisons.

Abstract: A system and method for performing independent, off-line evaluation of event sensing for collected electrograms, comprising: sensing an electrogram using an implantable medical device (IMD); determining locations of heart beats on at least one channel of the electrogram using a multi-pass process, resulting in a group of multi-pass beat locations; storing the electrogram and device-identified beat locations in a memory location; and retrieving the electrogram and device-identified beat locations from the memory location. The multi-pass process determines locations of heart beats on at least a first channel of the electrogram. The device-identified group of beat locations are then compared to the multi-pass group of beat locations identified using the multi-pass method. Based on the comparing step, oversensing of beats, undersensing of beats, or noise from the device can be detected.

Abstract: A system and method for performing off-line analysis of cardiac electrogram data, comprising: retrieving an electrogram from a memory location; identifying a first-channel group of candidate beats from at least a first channel of the electrogram; and identifying a second-channel group of candidate beats from at least a second channel of an electrogram. For each first-channel beat candidate near a second-channel beat candidate, the amplitude of the first-channel beat candidate is compared with the amplitude of a previous beat and the amplitude of a next beat on the first electrogram channel, and first-channel beat candidates that are outside of a first pre-determined range from either the previous or next beat are removed. Then first-channel beat candidates that are outside of a second pre-determined range from either the previous or next beat candidate are removed.

Abstract: This document discusses, among other things, systems and methods for automatic electrode integrity management. Interelectrode impedance is measured for various electrode combinations of an implantable cardiac function management device. The impedance data is processed, such as at an external remote server, to determine whether an electrode is failing or has failed, to select an alternate electrode configuration, to alert a physician or patient, to predict a time-to-failure such as by using population data, or to reprogram electrode configuration or other device parameters of the implantable cardiac function management device.

Abstract: Methods and systems for performing capture threshold tests are described. During an initialization procedure a capture detection interval and capture detection threshold are determined based on peak values of cardiac signals sensed following the supracapture threshold initialization pulses. Following initialization, a plurality of pacing pulses to the atrium are delivered and the peak values of the cardiac signals sensed following each of the plurality of pacing pulses are determined. The peak values are compared to the pacing artifact threshold and the capture detection threshold. A timing of each of the peak values is compared to the capture detection interval. For each pacing pulse, discrimination between a captured response, a noncaptured response, and a fusion response is based on the peak value and timing comparisons.

Abstract: Methods and systems are directed to selecting from a variety of capture verification modes. A plurality of capture verification modes, including a beat by beat capture detection mode and a capture threshold testing mode without intervening beat by beat capture detection is provided. An efficacy of at least one of the capture verification modes is evaluated, and based on the evaluation, a capture verification mode is selected.

Abstract: Methods and systems for performing capture threshold tests are described. During an initialization procedure a capture detection interval and capture detection threshold are determined based on peak values of cardiac signals sensed following the supracapture threshold initialization pulses. Following initialization, a plurality of pacing pulses to the atrium are delivered and the peak values of the cardiac signals sensed following each of the plurality of pacing pulses are determined. The peak values are compared to the pacing artifact threshold and the capture detection threshold. A timing of each of the peak values is compared to the capture detection interval. For each pacing pulse, discrimination between a captured response, a noncaptured response, and a fusion response is based on the peak value and timing comparisons.

Abstract: Approaches for adjusting the pacing energy delivered by a pacemaker are provided. Adjusting the pacing energy involves performing a plurality of capture threshold tests, each capture threshold test measuring a capture threshold of the heart. One or more measured captured thresholds are selected, including at least one capture threshold that is higher relative to other measured capture thresholds acquired by the plurality of capture threshold tests. The pacing energy is adjusted based on the one or more selected capture thresholds.