Introduction Pulmonary vein isolation using radiofrequency catheter ablation is the standard of care for patients with drug-refractory atrial fibrillation. The purpose of this pilot study was to examine the local unipolar electrogram (UEGM) modification characteristics of the different target areas of left atrium and the associated ablation index parameters during pulmonary vein isolation procedure. Methods The study analyzed ten patients who underwent pulmonary vein isolation using radiofrequency energy at our Centre in 2021. The local electrophysiological properties and ablation parameters of 15 designated areas of interest in the left atria targeted by radiofrequency catheter ablation were collected. Results Out of the ten patients, six were men (mean age 66 years) and the majority (n=8) had paroxysmal atrial fibrillation. UEGM modification was observed in every studied RF ablation lesion. The mean time to achieve the UEGM modification in the posterior wall was shorter than that of the anterior wall( 8.9 seconds vs 11.1 seconds, respectively). The time to achieve the UEGM modification for every target was significantly shorter than delivered ( p<.001). Conclusion This study demonstrated that during pulmonary vein isolation using radiofrequency energy, local UEGM modification, representing a real-time surrogate of transmural lesion creation, is achieved in significantly shorter time reaching the conventional Ablation Index-guided approach in current practice.