Impact of filter configurations on bipolar EGMs: An optimal filter setting for identifying VT substrates

Masateru Takigawa; Frederic Sacher; Claire Martin; Ghassen Cheniti; Josselin Duchateau; Thomas Pambrun; Nicolas Derval; Hubert Cochet; Meleze Hocini; Tasuku Yamamoto; Takuro Nishimura; Susumu Tao; Shinsuke Miyazaki; Masahiko Goya; Tetsuo Sasano; Michel Haissaguierre; Pierre Jais

doi:10.1111/jce.15997

Impact of filter configurations on bipolar EGMs: An optimal filter setting for identifying VT substrates

J Cardiovasc Electrophysiol. 2023 Aug;34(8):1708-1717. doi: 10.1111/jce.15997. Epub 2023 Jul 11.

Authors

Masateru Takigawa^{1

2

3

4}, Frederic Sacher^{1

2}, Claire Martin^{1

5

6}, Ghassen Cheniti^{1

2}, Josselin Duchateau^{1

2}, Thomas Pambrun^{1

2}, Nicolas Derval^{1

2}, Hubert Cochet^{1

2}, Meleze Hocini^{1

2}, Tasuku Yamamoto³, Takuro Nishimura³, Susumu Tao³, Shinsuke Miyazaki^{3

4}, Masahiko Goya¹, Tetsuo Sasano³, Michel Haissaguierre^{1

2}, Pierre Jais^{1

2}

Affiliations

¹ Department of Cardiac Pacing and Electrophysiology, Bordeaux University Hospital (CHU), Bordeaux, France.
² IHU Liryc, Electrophysiology and Heart Modeling Institute, University of Bordeaux, Bordeaux, France.
³ Department of Cardiovascular Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
⁴ Department of Advanced Arrhythmia Research, Tokyo Medical and Dental University, Tokyo, Japan.
⁵ Royal Papworth Hospital, Cambridge, UK.
⁶ Department of Medicine, Cambridge University, Cambridge, UK.

PMID: 37431258
DOI: 10.1111/jce.15997

Abstract

Background: The impact of filtering on bipolar electrograms (EGMs) has not been systematically examined. We tried to clarify the optimal filter configuration for ventricular tachycardia (VT) ablation.

Methods: Fifteen patients with VT were included. Eight different filter configurations were prospectively created for the distal bipoles of the ablation catheter: 1.0-250, 10-250, 100-250, 30-50, 30-100, 30-250, 30-500, and 30-1000 Hz. Pre-ablation stable EGMs with good contact (contact force > 10 g) were analyzed. Baseline fluctuation, baseline noise, bipolar peak-to-peak voltage, and presence of local abnormal ventricular activity (LAVA) were compared between different filter configurations.

Results: In total, 2276 EGMs with multiple bipolar configurations in 246 sites in scar and border areas were analyzed. Baseline fluctuation was only observed in the high-pass filter of (HPF) ≤ 10 Hz (p < .001). Noise level was lowest at 30-50 Hz (0.018 [0.012-0.029] mV), increased as the low-pass filter (LPF) extended, and was highest at 30-1000 Hz (0.047 [0.041-0.061] mV) (p < .001). Conversely, the HPF did not affect the noise level at ≤30 Hz. As the HPF extended to 100 Hz, bipolar voltages significantly decreased (p < .001), but were not affected when the LPF was extended to ≥100 Hz. LAVAs were most frequently detected at 30-250 Hz (207/246; 84.2%) and 30-500 Hz (208/246; 84.6%), followed by 30-1000 Hz (205/246; 83.3%), but frequently missed at LPF ≤ 100 Hz or HPF ≤ 10 Hz (p < .001). A 50-Hz notch-filter reduced the bipolar voltage by 43.9% and LAVA-detection by 34.5% (p < .0001).

Conclusion: Bipolar EGMs are strongly affected by filter settings in scar/border areas. In all, 30-250 or 30-500 Hz may be the best configuration, minimizing the baseline fluctuation, baseline noise, and detecting LAVAs. Not applying the 50-Hz notch filter may be beneficial to avoid missing VT substrate.

Keywords: Basic: activation mapping of arrhythmias; Basic: ventricular tachycardia/fibrillation; Clinical: cardiac mapping-electrogram analysis; Clinical: cardiac mapping-voltage.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Catheter Ablation* / adverse effects
Cicatrix
Humans
Tachycardia, Ventricular* / diagnosis
Tachycardia, Ventricular* / surgery