Effect of reference electrode on intracardiac electrograms: Close indifferent electrode vs Wilson central terminal

Tasuku Yamamoto, Masateru Takigawa, Takatoshi Shigeta, Claire A. Martin, Junji Yamaguchi, Miki Amemiya, Takashi Ikenouchi, Miho Negishi, Iwanari Kawamura, Kentaro Goto, Takuro Nishimura, Tomomasa Takamiya, Susumu Tao, Shinsuke Miyazaki, Masahiko Goya, Tetsuo Sasano

Research output: Contribution to journalArticlepeer-review

Abstract

Background: Unipolar electrograms (uni-EGMs) are an essential part of intracardiac mapping. Although Wilson central terminal (WCT) is conventionally used as a reference for signals, avoidance of contamination by far-field and nonphysiologic signals is challenging. Objective: The aim of the study was to explore the impact of an intracardiac indifferent reference electrode close to the recording electrodes, in lieu of WCT, on electrograms. Methods: Sinus node activation was mapped in patients undergoing catheter ablation by a multielectrode array with a close indifferent electrode (CIE) embedded in the distal end of the catheter shaft. An equal number of points was sequentially acquired at each site with use of CIE as a reference first and subsequently with WCT. Uni-EGMs, bipolar EGMs, and the earliest activation area (defined as the area activated in the first 10 ms of the beat) were compared between CIE- and WCT-based activation maps. Results: Seventeen patients (61 ± 18 years; 76% male) were studied. Uni-EGM voltages acquired with CIE were significantly larger than (n = 11) or comparable to (n = 4) those acquired with WCT. When points from the entire cohort were analyzed altogether, unipolar voltages and their maximum negative dV/dT and bipolar voltages recorded with CIE were significantly larger than those recorded with WCT (2.36 [1.42–3.79] mV vs 1.96 [1.25–3.03] mV, P < .0001; 0.40 [0.18–0.77] mV/s vs 0.35 [0.15–0.71] mV/s, P < .0001; and 1.46 [0.66–2.81] mV vs 1.33 [0.54–2.64] mV, P < .0001, respectively). The earliest activation area was significantly smaller in CIE-based activation maps than in WCT-based ones (0.3 [0.7–1.4] cm2 vs 0.6 [1.0–1.8] cm2, P = .01). Conclusion: CIE-based maps were associated with an approximately 20% increase in unipolar voltage and may highlight the origin of a focal activation more clearly than WCT-based ones.

Original languageEnglish
Pages (from-to)1382-1389
Number of pages8
JournalHeart Rhythm
Volume21
Issue number8
DOIs
StatePublished - Aug 2024
Externally publishedYes

Keywords

  • Bipolar
  • Electrograms
  • Mapping
  • Unipolar
  • Voltage

Fingerprint

Dive into the research topics of 'Effect of reference electrode on intracardiac electrograms: Close indifferent electrode vs Wilson central terminal'. Together they form a unique fingerprint.

Cite this