# The signal quality of tripolar Laplacian electrogram compared to bipolar electrogram in cardiac electrophysiology

## TL;DR

This study compares tripolar Laplacian electrograms to bipolar electrograms in cardiac electrophysiology, finding that tripolar Laplacian electrograms reduce noise and far-field potentials.

## Contribution

The study introduces evidence that tripolar Laplacian electrograms (TLE) are more effective than bipolar electrograms (BE) in reducing noise and far-field potentials in cardiac electrophysiology.

## Key findings

- TLE has a significantly lower voltage amplitude than BE across all activation patterns and wavefront angles.
- TLE reduces noise by 47% and far-field potentials more effectively than BE.
- TLE is more useful for analyzing low-voltage and fractionated electrograms in cardiac electrophysiology.

## Abstract

The usefulness of tripolar Laplacian electrogram (TLE) in cardiac electrophysiology is unknown.

We investigated the difference in the morphology, voltage amplitude, noise level, and far‐field potential (FFP) between TLE and bipolar electrogram (BE).

Twenty‐two patients who underwent catheter ablation for atrial fibrillation were analyzed. TLE and BE were simultaneously obtained using 64‐electrode basket catheters during atrial tachycardia or pacing. Local electrograms (EGMs) were analyzed at the locations of three activation patterns: normal conduction, wavefront collision, and slow conduction (SC). In addition, each activation pattern was analyzed at two different wavefront angles: horizontal and vertical, respectively. The voltage amplitude, duration, morphology, and deflection number were compared. The noise level and FFP amplitude were also analyzed.

With all activation patterns and wavefront angles, the voltage amplitude was significantly lower on TLE than on BE, and the mean amplitude ratio of TLE/BE was 0.75. The duration and deflection number of EGM were comparable. The ventricular FFP amplitude was lower on TLE than on BE (0.04 mV vs. 0.40 mV, p = .01). TLE also had less noise than BE (0.08 mV vs. 0.15 mV, p = .02), with a noise reduction of 47%. At the SC area, low‐voltage EGMs below the mean noise levels were more common with BE than with TLE (29% vs. 8%, p = .04).

TLE has a lower voltage amplitude than BE for all activation patterns and wavefront angles, and it removes more noise and FFPs. TLE is useful for analyzing low‐voltage and fractionated EGMs regardless of the wavefront angle.

Tripolar Laplacian electrogram (TLE) is one of the multipolar electrograms. TLE has a lower voltage amplitude than bipolar electrograms for all activation patterns and wavefront angles, and it removes more noise and far‐field potentials. TLE is useful for analyzing low‐voltage and fractionated electrograms regardless of the wavefront angle.