This is a prospective, randomized controlled, single-blind, multi-center clinical trial study aiming to investigate whether the strategy of posterior wall isolation (PWI) assisted by vein of Marshall ethanol infusion (VOMEI) could improve the success rate of persistent atrial fibrillation ablation.

A total of 260 participants with persistent AF who undergo radiofrequency catheter ablation and received VOMEI + PVI will be randomized assigned to two groups at 1:1 ratio.

Group 1: VOMEI + PVI + linear ablation + PWI; Group 2: VOMEI + PVI +linear ablation. The major endpoint (efficacy endpoint) is the recurrence of atrial tachyarrhythmias between 3-12 months during follow-up. The secondary endpoint (safety endpoint) is the occurrence of procedural complications.

Inclusion Criteria:

1. Between 18-85 years old;
2. Symptomatic, non-valvular persistent atrial fibrillation (atrial fibrillation duration ≥1 week), and refractory to at least one antiarrhythmic drug;
3. Prepared to undergo atrial fibrillation catheter ablation;
4. Provide informed consent to participate in the study, comply with follow-up trials and evaluation procedures.

Exclusion Criteria:

1. Presence of acute conditions such as acute phase after myocardial infarction (within 3 months), acute heart failure or new onset of cerebral infarction within 3 months;
2. On the heart transplant list;
3. Life expectancy less than 1 year;
4. With other bleeding disorders that cannot be treated with anticoagulation therapy;
5. With left atrial thrombus;
6. Heart failure with NYHA class III-IV or LVEF<40%;
7. With uncontrolled malignant tumor;
8. Obvious liver or kidney dysfunction (ALT, AST levels more than 2 times the upper limit of normal, and/or CCr<50%);
9. History of catheter radiofrequency ablation for atrial fibrillation or cardiac surgery;
10. Women who are pregnant, breastfeeding, planning to become pregnant, or of childbearing age but not using reliable contraception.

This study used a single-blind design for the subjects. A statistician created a random sequence of numbers using a randomization scheme. The sequence was then placed in opaque coded envelopes and sealed in numerical order. When a patient met the inclusion and exclusion criteria and was assigned a number, the researcher notified the manager to obtain the corresponding envelope and perform the intervention according to the grouping plan inside the envelope. Group 0 correspond to the control group not receiving PWI isolation, while group 1 correspond to the experimental group for PWI isolation.