https://doi.org/10.1007/s00392-025-02625-4
1Universitätsklinikum Schleswig-Holstein Innere Medizin III mit den Schwerpunkten Kardiologie und internistische Intensivmedizin Kiel, Deutschland; 2Universitätsklinikum Schleswig-Holstein Innere Medizin III mit den Schwerpunkten Kardiologie, Angiologie und internistische Intensivmedizin Kiel, Deutschland; 3Universitätsklinik Schleswig-Holstein, Campus Kiel Klinik für Kardiologie und internistische Intenisvmedizin Kiel, Deutschland
Introduction:
Atrial fibrillation (AF) is the most common arrhythmia worldwide and is associated with significant morbidity and mortality. Obesity is a risk factor of AF and the number of ablation procedures in obese patients increases every year. Obesity is associated with electroanatomical remodeling. However, data regarding the impact of obesity on voltage parameters of the left atrium (LA) is currently scarce.
Purpose:
This study aims to analyse the voltage characteristics of the LA in obese vs non-obese patients.
Methods:
Consecutive patients undergoing de novo pulmonary vein isolation (PVI) by a 3D high density mapping system between 01/2022 and 01/2024 were prospectively included. Two groups were defined (obese group: body mass index (BMI) ≥ 30 kg/m2; n =30; non-obese group: BMI <30 kg/m2; n = 37). Electroanatomical maps (EAMs) of the LA were analysed offline to identify low-voltage areas (bipolar voltage <0.5 mV for maps in sinus rhythm (SR) and <0.3 mV for maps in AF) and scar areas (<0.05 mV). Comparison is made fro the LA and segmentwise: roof, anterior, lateral, septal, posterior and compared in both obese vs. non-obese groups. The generated mesh data of the mapping system was exported and processed in Python to interpolate voltage measurements across the surface of the LA, creating a continuous voltage map. By isolating regions within specific voltage ranges and summing corresponding triangular face areas, LA regions with distinct electrical properties were quantified. An interactive platform ("Pulse") for visualizing and analyzing LA mapping was developed, aiming to explore electrical activity patterns and identify tissue abnormalities (Figure 1).
Results:
Altogether 67 patients were included (median age of 66 [IQR: 60.5-72] years; 39 patients [58.2%] male. Obese patients had higher level of HbA1c (p<0.05), while other baseline characteristics were comparable for both groups (Table 1). Of the obese patients, 15 (50%) maps were performed in AF and 15 (50%) in SR. Of the non-obese patients, 22 (59%) maps were performed in AF and 15 (40%) in SR (Figure 2).
The radiation dose was higher in obese patients (p<0.05), while fluoroscopy time and procedure duration were comparable in the obese and non-obese group (Table 2). For the bipolar voltage in left atrium, there were no significant differences either in the low voltage areas or in the scar areas, in total as well for the different anatomical segments (Table 3).
Conclusion:
No difference was identified regarding the size and distribution of low voltage areas in the LA in patients with obesity vs. non-obesity. Moreover, atrial volumes did not differ between the groups. Further research with a larger cohort is needed to better understand the relationship between obesity and atrial remodeling.