Efficacy and Safety of Pulsed Field Ablation in Refractory Mitral Isthmus-dependent Atrial Flutter: Pulsed Field Ablation Vs. Radiofrequency Ablation: a Preliminary Randomized Controlled Study

Inclusion Criteria: 1.Patients aged ≥18 years. 2.Diagnosed with persistent symptomatic refractory mitral valve commissural-dependent atrial flutter. Refractory mitral valve commissural-dependent atrial tachycardia is defined as: 1. Failure of drug therapy: At least one Class I or III antiarrhythmic drug (e.g., propafenone, amiodarone) fails to effectively control or prevent episodes. 2. Failure of catheter ablation: At least one previous attempt at radiofrequency catheter ablation (RFCA) targeting the mitral valve commissure has been unsuccessful (either due to recurrence post-procedure or failure to achieve bidirectional block at the commissure). 3.Intolerant to at least one antiarrhythmic drug (AAD). 4.The patient must be capable of and willing to provide written informed consent to participate in this study. Exclusion Criteria: 1. Pregnant or breastfeeding women. 2. Presence of left atrial thrombus on preoperative imaging. 3. Life expectancy less than 1 year. 4. Coagulation disorders or contraindications to anticoagulant therapy.