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: Wearable, automatic external, and implantable defibrillators, as well as methods of operation in such systems, are disclosed with shock delivery mitigations to avoid delivering a defibrillation shock on a T-wave. Prior to issuance of a defibrillation shock, one or more detected cardiac events are analyzed to characterize a detected event that is sensed for purposes of synchronizing the defibrillation shock. The detected event can be characterized as an R-wave or a T-wave, and the shock delivery protocol is then selected based on the characterization of the detected event to avoid shock-on-T and potential pro-arrhythmia.

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: 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: 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: 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: 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.