Pulsed-Field Ablation for Recurrent Atypical Atrial Flutter

Atypical atrial flutter (AFL) is a challenging atrial tachyarrhythmia that frequently occurs after prior catheter ablation for atrial fibrillation (AF) or AFL. Conventional radiofrequency ablation (RFA) can be limited by variable lesion size and depth, difficulty in achieving durable transmural linear block, and the risk of collateral injury to adjacent structures such as the esophagus, phrenic nerve, and coronary arteries. These limitations are particularly important in recurrent atypical AFL, where complex macro-reentrant or localized reentrant circuits often form along prior ablation scars or in regions of epicardial conduction in the posterior left atrium and pulmonary veins, making durable ablation difficult to achieve.

Pulsed-field ablation (PFA), based on non-thermal irreversible electroporation, has emerged as a promising technique that can create deep, contiguous lesions with preferential myocardial injury while sparing non-cardiac tissues. Early clinical experience with point-by-point PFA systems has demonstrated high acute and chronic success rates for pulmonary vein isolation and linear ablation with low complication rates in patients with recurrent AF or AFL after prior ablation. These data suggest that focal PFA may overcome some of the safety and efficacy limitations of conventional thermal energy sources.

This single-center, prospective, non-randomized, single-arm clinical investigation will enroll approximately 30 adult patients with clinically documented recurrent atypical AFL after prior AF/AFL ablation within 5 years who are scheduled for elective repeat ablation. The investigational system is the Biosense Webster Dual Energy Pulsed Field/Radiofrequency Ablation System, consisting of the TRUPULSE™ Generator, the Dual Energy THERMOCOOL SMARTTOUCH™ SF (STSF) catheter, and the CARTO™ 3 System with VISITAG SURPOINT™ Module. Standard-of-care adjunctive devices (e.g., OCTARAY™ mapping catheter, DECANAV™ diagnostic catheter, VIZIGO™ sheath, and intracardiac echocardiography \[ICE\] catheter) will be used as appropriate.

Eligible subjects are ≥18 years of age with recurrent atypical AFL documented by ECG or electrophysiologic study after prior pulmonary vein isolation and/or AFL ablation, including gap-reentrant, perimetral, roof-dependent, bi-atrial, or scar-related circuits, and who are willing and able to provide informed consent and complete follow-up. Key exclusion criteria include AFL due to reversible causes, recent major cardiac events or surgery, significant structural heart disease (e.g., severe valvular disease, hypertrophic cardiomyopathy, markedly enlarged left atrium), severe ventricular dysfunction, significant pulmonary or renal disease, active malignancy or infection, untreated severe sleep apnea, contraindication to anticoagulation, pregnancy, vulnerable populations, and limited life expectancy.