Pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF) has limited success. The superior vena cava (SVC) has been identified as one of the most common non-pulmonary vein triggers for PAF. It is estimated that SVC isolation (SVCI) could improve the clinical results for patients with PAF. However, results from previous studies about SVCI remain controversial. It is possible that safety concerns for SVCI outweigh its benefits and lead to inadequate ablation. To address this issue, the introduction of a quantitative ablation index (AI) for SVCI may provide a solution. The goal of this prospective, randomized controlled trial is to test the efficacy and safety of quantitative SVCI in addition to PVI in PAF. Participants with PAF will be randomly assigned to either PVI group or PVI+ quantitative SVCI group in a 1:1 ratio and will be followed up for 12 months. The main questions it aims to answer are: 1. Evaluate the efficacy of PVI+SVCI guided by quantitative AI. 2. Assess the safety of PVI+SVCI guided by quantitative AI. The primary end point is treatment success at 3 months after the index ablation. The secondary end points include treatment success at 12 months, and safety outcomes.