PO-04-136 VISUALIZATION OF LOW AMPLITUDE ELECTROGRAMS WITH A NOVEL RECORDING SYSTEM IN THE ELECTROPHYSIOLOGY LABORATORY

Abstract

Electrical noise, particularly power line noise at 50-60 Hz, is frequently generated by electrical equipment present in the electrophysiology (EP) laboratory. High frequency, low amplitude intracardiac unipolar and bipolar electrograms (EGMs) are particularly susceptible to distortion from this type of noise. The aim of this study was to evaluate a novel EP recording system developed to address this issue. To measure baseline noise and the smallest identifiable EGMs in a range of procedures. We enrolled patients undergoing catheter ablation of atrial flutter, atrial fibrillation (de novo as well as redo), SVT and conduction system pacemaker implantation. The peak-to-peak noise and intracardiac unipolar and bipolar signal amplitude was measured manually, initially side-by-side using the LabSystem (LS) Pro (Boston Scientific) and ECGenius System (CathVision) systems and then ECGenius System alone (Figure). EGMs were chosen to represent the lowest peak to peak amplitude of signals where information was of interest. A total of 37 consecutive patients were enrolled. The amplitude of the baseline noise measured on the LSPro system using standard filtering including a 60Hz notch filter was > 0.040 mV bipolar and > 0.100 mV unipolar. In contrast, on the ECGenius System the measured peak to peak baseline noise amplitude had a mean value of 0.010 ± 0.004 mV and 0.014 ± 0.018 mV for bipolar and unipolar EGMs, respectively using standard filter settings (Table). A mean noise level of 0.011 mV ± 0.005 was measured through a pacing lead allowing signals as low as 0.023 mV to be observed. The ability to visualize low amplitude intracardiac EGMs is essential during EP procedures. However, EGMs, especially unipolar EGMs, can be obscured by noise, most commonly due to power line interference. We demonstrate that a novel EP recording system had a mean noise level of only 0.010 mV with a low-end of 0.004 mV for bipolar signals. This allowed identification of intracardiac EGMs with a peak-to-peak voltage as low as 8 μV. These characteristics offer the possibility of improving outcomes during EP procedures and may also facilitate physiologic pacing through the identification of small His and bundle branch potentials.Tabled 1ECGenius measurements of baseline noise and lowest clinical EGM amplitude observed by catheter and trace typeBaselineLowest ClinicalminmeanStd.Dev.minmeanSt.Dev.Catheter TypeOrion0.0050.0130.0140.0270.0560.085Pentarray0.0040.0090.0050.0080.0290.035Ablation0.0050.0110.0030.0230.0370.015Pacemaker Lead0.0080.0110.0050.0230.0950.149EGM TypeUnipolar0.0080.0140.0180.0350.0900.138EGM TypeBipolar0.0040.0100.0040.0080.0330.026 Open table in a new tab