Frequency Gradient Within Coronary Sinus Predicts the Long‐Term Outcome of Persistent Atrial Fibrillation Catheter Ablation

Abstract

Background The coronary sinus ( CS ), as a junction of the atria, contributes to atrial fibrillation ( AF ) by developing unstable reentry, and isolating the atria by ablation at the CS could terminate AF . The present study evaluated whether AF activities at the CS in a subset of patients contributed to AF maintenance and predicted clinical outcome of ablation. Methods and Results We studied 122 consecutive patients who had a first‐time radiofrequency ablation for persistent AF . Bipolar electrograms were obtained from multiple regions of the left atrium by a Lasso mapping catheter before ablation. Pulmonary vein isolation terminated AF in 12 patients (9.8%). Sequential stepwise ablation was conducted in pulmonary vein isolation nontermination patients and succeeded in 22 patients (18%). In the stepwise termination group, AF frequency in the proximal CS ( CS p) was significantly higher (10.2±2.1 Hz versus 8.3±1.8 Hz, P <0.001), and the ratio of distal CS ( CS d) to proximal CS ( CS d/ CS p ratio, 56.6%±10.11% versus 70.7%±9.8%, P <0.001) was significantly lower than that in the nontermination group. The stepwise logistic regression analysis indicated that the CS d/ CS p ratio was an independent predictor with an odds ratio of 1.131 (95% CI 1.053‐1.214; P =0.001). With a cutoff of 67%, the patients with lower CS d/ CS p ratios had significantly better index and long‐term outcomes than those with higher ratios during a follow‐up of 46±18 months. Conclusions Rapid repetitive activities in the musculature of the proximal CS may contribute to maintenance of AF after pulmonary vein isolation alone in persistent AF . A cutoff at 67%, of the CS d/ CS p frequency ratio might be an indicator to stratify the subset of patients who might benefit from CS ablation.