Abstract: An implantable cardiac device is configured to classify cardiac arrhythmias using a plurality of arrhythmia discrimination algorithms. Data is provided that is associated with a plurality of cardiac arrhythmic episodes for which a cardiac electrical therapy was delivered or withheld by the implantable medical device based on the plurality of arrhythmia discrimination algorithms. A metric for each of the arrhythmic episodes is computed. The metric defines a measure by which the implantable cardiac device properly classified the arrhythmia. Potentially misclassified arrhythmic episodes of the plurality of cardiac arrhythmic episodes for which cardiac electrical therapy was inappropriately delivered or withheld are algorithmically identified using the metric.

Abstract: A system for reducing proarrhythmic effects of neural stimulation is provided. One aspect of this disclosure relates to an implantable medical device (IMD) for reducing proarrhythmic effects of neural stimulation. The IMD includes a neural stimulator adapted to deliver an electrical signal through at least one electrode to provide vagal stimulation. The IMD also includes a controller adapted to receive atrial arrhythmia vulnerability data and to control a therapeutic stimulator to limit atrial proarrhythmia using the atrial arrhythmia vulnerability data. The controller is further adapted to receive atrial arrhythmic history data and to control a therapeutic stimulator to limit atrial proarrhythmia using the atrial arrhythmic history data, according to various embodiments. According to one embodiment, the therapeutic stimulator includes the neural stimulator. The therapeutic stimulator includes a cardiac stimulator adapted to provide cardiac rhythm management therapy, according to various embodiments.

Abstract: Systems and methods provide for selection of automatic capture verification modes. A number of capture verification modes are evaluated, wherein at least one of the capture verification modes has a distinct temporal relationship between delivery of a pacing pulse and detection of capture of heart tissue by the pacing pulse than the other capture verification modes. One or more capture verification modes are selected based on the evaluation. Capture verification is implemented using the selected one or more capture verification modes.

Abstract: The waveform morphology of a propagated pacing response signal may be adjusted to achieve a waveform morphology that enhances cardiac pacing response determination. One or more pacing intervals may be adjusted to achieve at least one cardiac pacing response waveform morphology that enhances determination of the cardiac pacing response. The heart is paced using the one or more adjusted pacing intervals and the cardiac response to the pacing is determined. The one or more adjusted pacing intervals may include an atrioventricular pacing delay, an interatrial pacing delay, an interventricular pacing delay, or other inter-chamber or inter-site pacing delays. Adjusting the one or more pacing intervals may be used to increase a difference between a first waveform morphology associated with multi-chamber capture and a second waveform morphology associated with single chamber capture.

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 devices for reducing phrenic nerve stimulation of cardiac pacing systems involve delivering a pacing pulse to a ventricle of a heart. A transthoracic impedance signal is sensed, and a deviation in the signal resulting from the pacing pulse may be used to determine phrenic nerve stimulation. Methods may further involve detecting the phrenic nerve stimulation from the pacing pulse by delivering two or more pacing pulse to the ventricle of the heart, and determining a temporal relationship. A pacing vector may be selected from the two or more vectors that effects cardiac capture and reduces the phrenic nerve stimulation. A pacing voltage and/or pulse width may be selected that provides cardiac capture and reduces the phrenic nerve stimulation. In other embodiments, a pacing pulse width and a pacing voltage may be selected from a patient's strength-duration curve that effects cardiac capture and reduces the phrenic nerve stimulation.

Abstract: Methods and systems involve determining the cardiac response to pacing pulses. The variability cardiac signal features detected during initialization is used to establish a variability threshold. A cardiac signal associated with a pacing pulse is sensed and one or more features of the cardiac signal are detected. The variability of the one or more features is compared to the variability threshold. The cardiac response to the pacing pulse is determined based on the feature variability.

Abstract: Cardiac treatment methods and devices provide for templates representative of past tachyarrythmia events, each template associated with a therapy. Methods involve providing a cardiac waveform representative of a patient's cardiac activity and identifying a portion that indicates an arrhythmic event. A cardiac template corresponding to the portion is generated, and a therapy is associated with the template useful for treating a subsequent arrhythmia. The waveform portion may be identified by a physician using a patient-external device to display the cardiac waveform. The template may be generated by a physician selecting the cardiac waveform, and determining if the therapy associated with the template was satisfactory and/or effective in treating the arrhythmia. Identification may involve matching the event to templates generated using cardiac waveforms other than the patient's cardiac waveforms.