Abstract 17454: the Effect of Catheter Ablation on Coronary Sinus Cycle Length in Persistent Atrial Fibrillation

Background: While pulmonary vein isolation (PVI) for treatment of persistent atrial fibrillation (PeAF) is successful in approximately 50%, acute termination of PeAF is rarely observed. Prolongation of cycle length (CL) by 10% is often utilized as an indicator of successful catheter ablation (CA). Objective: To evaluate coronary sinus (CS) cycle length (CL) before and after CA for PeAF. Methods: CA for PeAF was performed in 31 patients (24males, age 63±9 yrs, CHA2DS2-VASc 2.3±1.7, LVEF 49±10%) with PVI, with 4 (13%) also having posterior wall isolation. A multielectrode catheter was placed in the CS and maintained throughout the procedure. CS electrograms were recorded for 10 seconds prior to CA and after completion of CA. No patient reverted to sinus rhythm during CA. CS CL was determined using customized software for activation detection and verified visually, excluding ventricular activation and low quality signals (n=3). The shortest CL among the recording electrodes was used for analysis. Results: CS CL pre- and post-CA were 182.4±23.0 and 191.6± 29.9 ms (p= 0.04) with change from baseline of 5.4±12.7%. The figure shows the histogram for change in CS CL from baseline. Only 7/28 (25%) of patients had CS CL prolongation >10%. Of ten patients who were free of AF off anti-arrhythmic drugs at 1 year, CS CL increased 4.0±6.1%; 2/10 had CS CL prolongation >10%. Of 6 patients with recurrent AF, CS CL increased 13.8±20.7%; 4/6 had CS CL prolongation >10%. Conclusion: Our data demonstrate that CS CL prolongation >10% is not a useful marker of outcomes in patients undergoing catheter ablation for PeAF. This highlights the need to identify other indicators of acute ablation success.