PO-700-08 ELIMINATION OF HARMONIC RINGING IN INTRACARDIAC SIGNALS USING DYNAMIC ALGORITHMIC NOTCH FILTERING

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The use of classic notch (CN) and bandpass (BP) filters on intracardiac electrogram (EGM) channels have long been considered the best options for correcting environmental noise in the EP lab. Due to the steep transitions and narrowness of the bandwidth, these filters can alter signal morphology, producing artificial harmonic ringing and additional deflections that may be misinterpreted as physiologic signal fractionation. CN and BP are often automatically preprogrammed on EGM channels without further consideration. While filtering to remove baseline wander is still required to properly interpret signals, an alternative solution that doesn’t generate harmonic ringing and artificial fractionation would improve the confidence and accuracy in identifying abnormal signals. To characterize the impact of CN and BP filters on EGM signals during ablation procedures and evaluate the Algorithmic Notch (AN) filter within the PURE EP™ system (PURE) (BioSig Technologies). Signals of clinical interest were assessed during 20 re-do AF ablation procedures that compared signals between PURE and the GE Cardiolab system. Using PURE the signals from the same intracardiac channel were run simultaneously using different filter settings. A control channel was run with only a high pass filter of 5Hz to remove some baseline wander. The same signals were subsequently compared to the control with three different filter settings: 1) a high pass filter of 10Hz + PURE AN 2) a high pass filter of 10Hz + CN, and 3) a BP 30-500Hz + CN. The AN on PURE was consistently the most successful in removing baseline artifact without significantly altering the morphology or signal characteristics. The appearance of artificial deflections resembling physiologic fractionation were seen in the latter two groups and signal amplitudes were attenuated by 30-40% when compared to the PURE AN group. The AN in PURE can eliminate environmental noise without harmonic ringing, morphological changes, or attenuation seen with CN and BP filtering.