Atrial fibrillation (AF) is a common heart rhythm disorder. While catheter ablation is an effective treatment, many patients still experience AF recurrence after the procedure. One major reason is that the mechanisms that maintain AF are not fully understood. Research suggests that the outer layer of the heart (epicardium) may play an important role in keeping AF going. However, current mapping techniques have limitations in detecting electrical signals from both the inner and outer heart layers.

This study uses a different technique called unipolar voltage mapping, which may more accurately capture electrical signals from both heart layers. Specifically, we focus on a specific type of electrical signal called "QS potential" on unipolar mapping, which reflects breakthrough sites between the inner and outer heart layers.

In this interventional study, participants with AF undergoing catheter ablation will receive personalized ablation guided by unipolar QS-potential mapping. We aim to:

Explore the relationship between unipolar QS-potentials and AF maintenance and atrial remodeling Evaluate the effectiveness of QS-potential guided personalized AF ablation

Inclusion Criteria:

• Age ≥ 18 years and ≤ 80 years
• Documented diagnosis of atrial fibrillation (paroxysmal or persistent)
• Planned to undergo catheter ablation for AF (including patients with recurrent AF after prior ablation)
• Able and willing to provide written informed consent
• Able to complete scheduled follow-up visits (3 months post-ablation)

Exclusion Criteria:

• Left ventricular ejection fraction < 35%
• Severe valvular heart disease (moderate to severe mitral stenosis or regurgitation)
• History of intracardiac thrombus
• Contraindication to anticoagulation
• Active infection or sepsis
• Pregnancy or breastfeeding
• Life expectancy < 12 months due to comorbid conditions
• Participation in another interventional clinical trial within 30 days prior to enrollment