Comparison Between Upgraded '2C3L' vs. PVI Approach for Catheter Ablation of Persistent Atrial Fibrillation

Patients randomized to the upgraded '2C3L' arm will first undergo EI-VOM, followed by the '2C3L' ablation step. The details include: (1). EI-VOM procedure: An 8.5-French-long sheath or a steerable long sheath is sent to the coronary sinus (CS) via the femoral vein. A JR4.0 catheter is inserted into the CS to identify the ostium of the VOM. Subsequently, a BMW wire supported by an OTW balloon catheter is advanced into the VOM. The balloon is inflated with 6 to 8 atm in the VOM. A selective venogram of the VOM is obtained by slowly injecting 1 mL of contrast medium. Then, ethanol is slowly injected into the VOM and selective venography of the VOM is repeated. (2) . After EI-VOM, radiofrequency ablation was performed to achieve bilateral pulmonary vein isolation and bidirectional block of mitral isthmus line, roof line, and cavotricuspid isthmus line. (3). Any organized AT observed during the procedure will be targeted as well.

After reconstructing the left atrial geometry, PVI will be performed (the right PV antrum (PVA) will be ablated first, followed by the left PVA. ) in a wide area circumferential pattern. Complete PVI will be achieved when all PV potentials within each antrum recorded by the high-density mapping catheter are abolished. The endpoint of the circumferential PVA ablation procedure is to achieve electrical bilateral PV isolation, that is, the PV potentials associated with atrial electrical activity cannot be recorded during sinus rhythm or CS pacing (entrance block). A waiting period of at least 20 min (after the last PV is isolated) will be used during which spontaneous PV reconnection will be related. , and tDemonstration of exit block (he by pacing in the PV cannot be and proving the absence of transmitted conduction to capture the atrium) may be performed but is not mandatory. Any organized AT observed during the procedure will be targeted as well.