# Comparative cardiac electrophysiological analysis between sinus rhythm and atrial fibrillation: The correlation of left atrial low-voltage substrate of sex and rhythm

## TL;DR

This study finds that voltage cutoffs for heart tissue differ based on rhythm and sex, suggesting new guidelines for atrial fibrillation.

## Contribution

The study introduces region-specific and sex-adjusted voltage cutoffs for atrial fibrillation, improving electrophysiological analysis.

## Key findings

- A cutoff of 0.27 mV in AF predicts a sinus rhythm voltage of 0.5 mV.
- Region-specific cutoffs vary, such as 0.19 mV for the posterior wall and 0.17 mV for the inferior wall.
- Sex differences were observed, with males at 0.13 mV and females at 0.32 mV.

## Abstract

It is uncertain whether bipolar voltage cutoffs should be adjusted based on rhythm, sex, or region.

This study aimed to determine (1) the bipolar voltage cutoff values for the entire left atrium (LA) and the low-voltage areas in different regions of the LA and (2) whether sex-based differences exist in the bipolar voltage cutoff points for low-voltage areas.

30 patients with persistent atrial fibrillation (AF) underwent high-density voltage mapping first in sinus rhythm and subsequently during induced AF. The 7 parts of the map are respectively taken from 9 regions with the same position and location. The average low voltage of these area points was analyzed. Correlation was assessed using scatter plots, and agreement was evaluated with Bland-Altman analysis. The generalized additive model was used to predict the bipolar voltage cutoff points.

A total of 1268 regions were obtained. For the entire LA, a cutoff of 0.27 mV in AF predicted a sinus rhythm voltage of 0.5 mV (95% confidence interval 0.12–2.02). Region-specific AF voltage cutoffs were as follows: posterior wall 0.19 mV, inferior wall 0.17 mV, anterior wall 0.27 mV, LA appendage 0.27 mV, and roof 0.45 mV. Regarding different sexes, the values were 0.13 mV for males and 0.32 mV for females, respectively.

It is possible to establish a new cutoff value for AF with acceptable validity in predicting sinus voltage of <0.5 mV, but sex differences need to be taken into account.