Efficacy and Safety of Superior Vena Cava Isolation and Pulmonary Vein Isolation for Treatment of Atrial Fibrillation

Atrial fibrillation (AF) is one of the most concerning diseases in the field of cardiac arrhythmias. It is a type of rapid supraventricular arrhythmia characterized by rapid and disorganized contraction of the atria, which leads to ventricular rate disturbance, impaired cardiac function, and an increased risk of atrial mural thrombus formation. AF severely reduces patients' quality of life and can cause complications such as heart failure, stroke, and sudden death. Currently, the vast majority of AF episodes are triggered by pulmonary vein (PV) ectopic foci. Therefore, catheter ablation is the preferred treatment strategy, with pulmonary vein isolation (PVI) being the cornerstone procedure. However, a small proportion of patients may have non-PV triggers, particularly originating from the superior vena cava (SVC). Conventional radiofrequency ablation (RFA) for SVC isolation carries unpredictable risks, including damage to the sinus node and the phrenic nerve. Therefore, this study aims to investigate the impact of empirical SVC electrical isolation in addition to PVI on the success rate of AF ablation, using pulsed field ablation (PFA)-a non-thermal ablation modality with tissue selectivity and a favorable safety profile.

Inclusion Criteria: * Age ≥ 18 years; * Patients with documented atrial fibrillation (AF), confirmed by at least one episode of AF recorded on a 12-lead surface electrocardiogram (ECG) or ambulatory ECG monitoring within the past 12 months; * Subjects who agree to undergo treatment for AF using a pulsed field ablation (PFA) system that is currently commercially available in China; * Patients who have shown an inadequate response to, or intolerance of, at least one class of antiarrhythmic drug therapy; * Subjects or their legally authorized representatives who have been informed of the nature of this study, have agreed to all terms and conditions of the study, and have provided written informed consent, and who are willing to complete all required clinical follow-up visits in accordance with the study protocol. Exclusion Criteria: * Prior surgical or catheter ablation for any type of cardiac arrhythmia; * AF secondary to electrolyte imbalance, valvular heart disease, thyroid disease, or other reversible causes; * Known requirement for ablation outside the pulmonary vein ostia or beyond the cavotricuspid isthmus; * Sinus node dysfunction or other indications for permanent pacemaker implantation; * Myocardial infarction, or prior coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI) within the past 6 months; * Left atrial anteroposterior diameter ≥ 50 mm; * Evidence of left atrial or left atrial appendage thrombus confirmed by transesophageal echocardiography (TEE) or left atrial computed tomography (CT) within 24 hours prior to the procedure; * Serum creatinine \> 2 times the upper limit of normal, or currently on dialysis; * History of prior cardiothoracic surgery; * History of permanent pacemaker implantation; * History of malignancy; * Long-term use of a central venous catheter; * Contraindications to anticoagulation therapy (including allergy to anticoagulants, thrombocytopenia, severe bleeding tendency, or coagulation disorders); * History of allergy to contrast; * Women who are pregnant, lactating, or who are unwilling to use adequate contraception during the study period; * Subjects or their legally authorized representatives who are unwilling to provide written informed consent; * Subjects who, for any reason, are unable to comply with the study protocol or complete all required clinical follow-up visits; * Subjects deemed by the investigator to be unsuitable for PFA treatment of AF.