Pulmonary Veins to Left Atrium Cycle Length Gradient Predicts Procedural and Clinical Outcomes of Persistent Atrial Fibrillation Ablation

Background— Rapid pulmonary vein (PV) activity has been shown to maintain paroxysmal atrial fibrillation (AF). We evaluated in persistent AF the cycle length (CL) gradient between PVs and the left atrium (LA) in an attempt to identify the subset of patients where PVs play an important role. Methods and Results— Ninety-seven consecutive patients undergoing first ablation for persistent AF were studied. For each PV, the CL of the fastest activation was assessed over 1 minute (PV fast ) using Lasso recordings. The PV to LA CL gradient was quantified by the ratio of PV fast to LA appendage (LAA) AF CL. Stepwise ablation terminated AF in 73 patients (75%). In the AF termination group, the PV fast CL was much shorter than the LAA CL resulting in lower PV fast /LAA ratios compared with the nontermination group (71±10% versus 92±7%; P fast /LAA ratios were notably lower if AF terminated after PV isolation or limited adjunctive substrate ablation compared with patients who required moderate or extensive ablation (63±6% versus 75±8%; P fast /LAA ratio fast /LAA ratios P Conclusions— The PV to LA CL gradient may identify the subset of patients in whom persistent AF is likely to terminate after PV isolation or limited substrate ablation and better long-term outcomes are achieved.