Background: Low-voltage area (LVA) ablation, in addition to pulmonary vein isolation (PVI), has been proposed as a new strategy in patients with atrial fibrillation (AF), but clinical trials have shown conflicting results. We performed a systematic review and meta-analysis to assess the impact of LVA ablation in patient undergoing AF ablation (PROSPERO-registered CRD42024537696). Methods: Randomized clinical trials investigating the role of LVA ablation in addition to PVI in patients with AF were searched on PubMed, Embase, and the Cochrane Library from inception to 22 April 2024. Primary outcome was atrial arrhythmia recurrence after the first AF ablation procedure. Secondary endpoints included procedure time, fluoroscopy time, and procedure-related complication rate. Sensitivity analysis including only patients with LVA demonstration at mapping and multiple subgroups analyses were also performed. Results: 1547 patients from 7 studies were included. LVA ablation in addition to PVI reduced atrial arrhythmia recurrence (odds ratio [OR] 0.65, 95% confidence interval [CI] 0.52–0.81, p < 0.001) with a number needed to treat to prevent recurrence of 10. No difference in procedure time (mean difference [MD] −5.32 min, 95% CI −19.01–8.46 min, p = 0.45), fluoroscopy time (MD −1.10 min, 95% CI −2.48–0.28 min, p = 0.12) and complication rate (OR 0.81, 95% CI 0.40–1.61, p = 0.54) was observed. Consistent results were demonstrated when considering only patients with LVA during mapping and in prespecified subgroups for AF type (paroxysmal vs. persistent), multicentric vs. monocentric trial, and ablation strategy in control group. Conclusions: In patients with AF, ablation of LVAs in addition to PVI reduces atrial arrhythmia recurrence without a significant increase in procedure time, fluoroscopy time, or complication rate.

Background. Pulmonary vein isolation (PVI) represents the cornerstone of paroxysmal (PAF) and persistent atrial fibrillation (PsAF) ablation. Impedance values provide insights on tissue conductive properties. Methods. Consecutive patients undergoing PAF and PsAF ablation were prospectively enrolled. All the patients underwent a preprocedural multidetector computed tomography (MDCT) to evaluate left atrial wall thickness (LAWT). Electroanatomic maps were acquired with the ablation catheter, and impedance values (Ω) and voltage amplitude (mV) of bipolar electrograms were collected. Results. A total of 60 patients (40 with PAF and 20 with PsAF) were included in the study. In all PAF cases, no voltage value lower than 0.5 mV was found at LA mapping; the corresponding mean impedance value was 151.5 ± 5.4 Ω. In PsAF cases, voltage values inferior to 0.05 mV have been reported in 19/20 patients. PsAF patients showed a mean impedance value of 129.1 ± 3.8 Ω. The correlation analysis between bipolar voltage and impedance reported an r_s value of 0.4166 (p < 0.001), showing a positive correlation between the two variables. On the contrary, no direct correlation was found between voltage and LAWT and between impedance and LAWT (rsv-t = 0.1838; rsi-t = 0.1133, respectively). Conclusions. This research study suggests a correlation between voltage amplitude and impedance values, so that impedance might be used for arrhythmogenic substrate characterization.