Abstract: In some examples, cardiac cycle detection may be used as a more or less default approach to cardiac activity tracking. Additional rate measurement relying on different sources or analyses may require extra power consumption over the cycle detection methods. Therefore, new methods and devices are disclosed that selectively activate a second cardiac rate measurement when needed. In some illustrative methods and devices, decisions are made as to whether and which previously collected data, if any, is to be discarded, replaced, or corrected upon activation of the second cardiac rate measurement.

Abstract: An apparatus comprises a stimulus circuit, a cardiac signal sensing circuit, and a control circuit. The stimulus circuit provides electrical pulse energy to a first pacing channel that includes a first left ventricular (LV) electrode as a cathode and a second pacing channel that includes a second LV electrode as a cathode. The cardiac signal sensing circuit senses cardiac signals using a first sensing channel that includes one of the first LV electrode or the second LV electrode. The control circuit includes a capture detection sub-circuit configured to: initiate delivery of electrical pulse energy to both the first pacing channel and the second pacing channel; sense cardiac depolarization of a ventricle using the first sensing channel; determine first and second cardiac capture pulse energy level thresholds for the first and second pacing channels respectively; and provide indications of the cardiac capture pulse energy level thresholds to a user or process.

Abstract: Methods and devices for combining multiple signals from multiple sensing vectors for use in wearable or implantable cardiac devices. Signals from multiple vectors may be combined using weighting factors and/or by conversion to different coordinate systems than the original inputs, which may or may not be normalized to patient anatomy. Signals from multiple sensing vectors may be combined prior to or after several analytical steps or processes including before or after filtering, and before or after cardiac cycle detection. Cardiac cycle detection information may be combined across multiple sensing vectors before or after analysis of individual vectors for noise or overdetection. Cardiac cycle detection information may also be combined across multiple sensing vectors to identify noise and/or overdetection.

Abstract: Methods and devices for combining multiple signals from multiple sensing vectors for use in wearable or implantable cardiac devices. A preferred sensing configuration may be selected at a given point in time, for example under clinical conditions. Signal quality for the preferred sensing configuration is then monitored, and if the signal quality degrades under selected conditions, re-analysis may be performed to select a different sensing vector configuration for at least temporary use. If signal quality increases for the preferred sensing configuration, temporary use of the different sensing vector configuration may cease and reversion to the preferred sensing configuration takes place if certain conditions are met. The conditions for reversion may depend in part of a history of sensing signal quality for the preferred sensing configuration.

Abstract: Methods and devices for combining multiple signals from multiple sensing vectors for use in wearable or implantable cardiac devices. Signals from multiple vectors may be combined using weighting factors and/or by conversion to different coordinate systems than the original inputs, which may or may not be normalized to patient anatomy. Signals from multiple sensing vectors may be combined prior to or after several analytical steps or processes including before or after filtering, and before or after cardiac cycle detection. Cardiac cycle detection information may be combined across multiple sensing vectors before or after analysis of individual vectors for noise or overdetection. Cardiac cycle detection information may also be combined across multiple sensing vectors to identify noise and/or overdetection.

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: Systems and methods may facilitate selection of a vector for delivering electrical stimulation to a patient's heart. One illustrative method may include delivering electrical stimulation at a first voltage to each vector in a first set of two or more vectors of a multi-vector medical system, determining whether the delivered electrical stimulation at the first voltage resulted in capture for each of the vectors in the first set of two or more vectors, identifying those vectors of the first set of two or more vectors that were determined to result in capture as a second set of vectors, delivering electrical stimulation at a second voltage that is lower than the first voltage to each vector in the second set of vectors, and determining whether the delivered electrical stimulation at the second voltage resulted in capture for each of the vectors in the second set of vectors.

Abstract: An apparatus includes a sensing circuit configured to generate a sensed physiological signal representative of cardiac activity of a subject, an arrhythmia detection circuit, a control circuit, and a memory. The arrhythmia detection circuit detects an episode of atrial fibrillation (AF) in the sensed cardiac signal using a first AF detection criterion, and detects the episode of AF using a second AF detection criterion. The first AF detection criterion has greater sensitivity to AF detection than the second AF detection criterion, and the second AF detection criterion has greater specificity to AF detection than the first AF detection criterion. The control circuit initiates storing of sampled values of a segment of the cardiac signal that includes the episode of AF when the episode of AF is detected by both the first AF detection criterion and the second AF detection criterion.

Abstract: Systems and methods for providing CRT therapy to a patient with an implanted multi-site pacing medical device. In one example, an intrinsic electrical delay associated with each of two or more left ventricle electrodes may be determined. The intrinsic electrical delay associated with each of the two or more left ventricle electrodes may be compared to an electrical delay threshold. If the electrical delay associated with one or fewer left ventricle electrodes is greater than the electrical delay threshold, a single left ventricle electrode may be selected for use during subsequent CRT therapy. If the electrical delay associated with more than one left ventricle electrode is greater than the electrical delay threshold, two or more of the left ventricle electrodes may be selected for use during subsequent CRT therapy.

Abstract: Systems and methods for providing CRT therapy to a patient with an implanted multi-site pacing medical device. In one example, an intrinsic electrical delay associated with each of two or more left ventricle electrodes may be determined. The intrinsic electrical delay associated with each of the two or more left ventricle electrodes may be compared to an electrical delay threshold. If the electrical delay associated with one or fewer left ventricle electrodes is greater than the electrical delay threshold, a single left ventricle electrode may be selected for use during subsequent CRT therapy. If the electrical delay associated with more than one left ventricle electrode is greater than the electrical delay threshold, two or more of the left ventricle electrodes may be selected for use during subsequent CRT therapy.

Abstract: A system and method for cardiac rhythm management using a programmable cardiac rhythm management device is described, wherein the method includes storing parameter interaction constraints between different programmable parameters, storing programmable parameters for the device, wherein each programmable parameter has a predefined set of possible values, wherein one programmable parameter is a delay value, and calculating initial seed values for user-set delay range input fields, wherein the seed values do not violate any parameter interaction constraints and maximize the difference between ends of the user-set delay range, wherein the user-set delay range provides the outer limits of a programmed delay value. The method further includes presenting an input screen to the user on a user display device, wherein the input screen comprises user-set delay range input fields containing the initial seed values.

Abstract: An interactive representation of electrostimulation electrodes or vectors can be provided, such as for configuring combinations of electrostimulation electrodes. In an example, electrodes or test parameters can be presented graphically or in a table. A user interface can be configured to receive user-input designating electrode combinations or vectors for test or for use in programming an implantable or ambulatory medical device. The interface can be used to indicate suggested electrode combinations or vectors in response to a first selection of an electrode. Tests can be performed on electrode combinations and vectors, and the results of the tests can be presented to a user using the interactive representation. In an example, test results can be analyzed by a processor and optionally used to program an implantable or ambulatory medical device.

Abstract: Systems and methods may facilitate selection of a vector for delivering electrical stimulation to a patient's heart. One illustrative method may include delivering electrical stimulation at a first voltage to each vector in a first set of two or more vectors of a multi-vector medical system, determining whether the delivered electrical stimulation at the first voltage resulted in capture for each of the vectors in the first set of two or more vectors, identifying those vectors of the first set of two or more vectors that were determined to result in capture as a second set of vectors, delivering electrical stimulation at a second voltage that is lower than the first voltage to each vector in the second set of vectors, and determining whether the delivered electrical stimulation at the second voltage resulted in capture for each of the vectors in the second set of vectors.

Abstract: An interactive representation of electrostimulation electrodes or vectors can be provided, such as for configuring combinations of electrostimulation electrodes. In an example, electrodes or test parameters can be presented graphically or in a table. A user interface can be configured to receive user-input designating electrode combinations or vectors for test or for use in programming an implantable or ambulatory medical device. The interface can be used to indicate suggested electrode combinations or vectors in response to a first selection of an electrode. Tests can be performed on electrode combinations and vectors, and the results of the tests can be presented to a user using the interactive representation. In an example, test results can be analyzed by a processor and optionally used to program an implantable or ambulatory medical device.

Abstract: Some systems and methods may facilitate selection of a vector for delivering electrical stimulation to a patient's heart. One method may include displaying a plurality of vectors on a display screen wherein each vector represents a different combination of three or more electro-stimulation electrodes, determining an electrical impedance for each of the plurality of vectors, displaying on the display screen the electrical impedance for each of the plurality of vectors, receiving a selection of a set of the plurality of vectors, determining, for each of the vectors in the set of vectors, a capture threshold, displaying on the display screen the capture threshold for each of the vectors in the set of vectors, receiving a selection of a vector from the set of vectors for delivery of electrical stimulation to the patient's heart, and programming the electro-stimulation device electrical stimulation to the patient's heart via the selected vector.

Abstract: Systems and methods for efficiently determining one or more parameters for vectors of a multi-electrode implantable medical device, and for identifying one or more suitable vectors for sensing cardiac electrical data and/or delivering electrical stimulation therapy based on one or more of the determined parameters. Reducing the time required to determine the one or more parameters for each vector can help reduce procedure time for implanting and/or configuring an implantable medical device, which can reduce costs and/or improved patient comfort.

Abstract: Systems and methods for providing CRT therapy to a patient with an implanted multi-site pacing medical device. In one example, an intrinsic electrical delay associated with each of two or more left ventricle electrodes may be determined. The intrinsic electrical delay associated with each of the two or more left ventricle electrodes may be compared to an electrical delay threshold. If the electrical delay associated with one or fewer left ventricle electrodes is greater than the electrical delay threshold, a single left ventricle electrode may be selected for use during subsequent CRT therapy. If the electrical delay associated with more than one left ventricle electrode is greater than the electrical delay threshold, two or more of the left ventricle electrodes may be selected for use during subsequent CRT therapy.

Abstract: A system comprises a cardiac signal sensing and a processing circuit. The cardiac signal sensing circuit senses a first cardiac signal segment that includes a QRS complex and a second cardiac signal segment that includes a fiducial indicative of local ventricular activation. The processor circuit includes a site activation timer circuit configured to determine a time duration between a fiducial of the QRS complex of the first cardiac signal segment and the fiducial of the second cardiac signal segment. The processor circuit is configured to generate, using the determined time duration, an indication of optimality of placement of one or more electrodes for delivering therapy and provide the indication to at least one of a user or process.

Abstract: A system comprises a cardiac signal sensing and a processing circuit. The cardiac signal sensing circuit senses a first cardiac signal segment that includes a QRS complex and a second cardiac signal segment that includes a fiducial indicative of local ventricular activation. The processor circuit includes a site activation timer circuit configured to determine a time duration between a fiducial of the QRS complex of the first cardiac signal segment and the fiducial of the second cardiac signal segment. The processor circuit is configured to generate, using the determined time duration, an indication of optimality of placement of one or more electrodes for delivering therapy and provide the indication to at least one of a user or process.

Abstract: An apparatus comprises a cardiac signal sensing circuit, a stimulus circuit, and a control circuit. The control circuit includes a pacing site locating circuit that initiates a first electrical stimulus from a first electrode positioned in or near a first ventricle of a heart, determines a first time interval between delivery of the first electrical stimulus and a subsequent cardiac event sensed at a selectable electrode location in or near a second ventricle of the heart, initiates a second electrical stimulus at the selectable electrode location in or near the second ventricle, determines a second time interval between delivery of the second electrical stimulus and a subsequent cardiac event sensed at the first ventricle, calculates a difference between the first and second time intervals, and generates an indication of a preferred pacing site in the second ventricle according to the calculated differences between the first and second time intervals.