Introduction- Markers predicting AF termination and freedom from AF/atrial tachycardia (AT) has been proposed. The role of CS electrogram characteristics has not yet been evaluated. Methods- Patients undergoing ablation for persistent AF as part of the Stochastic Trajectory Analysis of Ranked signals mapping study were included. Novel CS electrogram characteristics including CS cycle length variability (CLV) and CS activation pattern stability (APS) and proportion of low voltage zones (LVZs) were reviewed as potential predictors for AF termination on ablation and freedom from AF/AT during follow-up. The relationship between localized driver characteristics and CS electrogram characteristics were also assessed. Results- Sixty-five patients were included. AF termination was achieved in 51 patients and 80% of patients were free from AF/AT during a follow-up of 29.5±3.7 months. CS CLV of <30ms, CS APS of ≥30% and proportion of LVZ <30% showed a high diagnostic accuracy in predicting AF termination on ablation and freedom from AF/AT during follow-up (CS CLV OR 25.6, AUC 0.91; CS APS OR 15.9, AUC 0.94; proportion of LVZs OR 21.4, AUC 0.88). These markers were independent predictors of AF termination on ablation and AF/AT recurrence during follow-up. Ablation of a smaller number of drivers that demonstrate greater dominance strongly correlate with greater CS organization. Conclusions- Novel CS electrogram characteristics were independent predictors of AF termination and AF/AT recurrence during follow-up. These markers can potentially aid in predicting outcomes and guide ablation and follow-up strategies.

Background: Although catheter ablation (CA) is an effective treatment for patients with AF and LVSD, the efficacy of an initial cryo-ablation strategy is unknown. This study evaluated long term outcomes of patients with an initial cryo-ablation strategy for AF and LV systolic dysfunction (LVSD). Methods: Outcomes of patients undergoing index cryoablation for AF from January 2008 until March 2018, with documented pre-ablation LVEF45% were evaluated for long term freedom from AF and change in ventricular function from baseline. Results: 76 patients met inclusion criteria. Patients were predominantly male (80%), aged 63 11yrs, with an average CHADS2 VASc score of 2.66  1.40, baseline LVEF 34  8.7% (ischaemic in 37%) and NYHA class 2.37  0.72. Repeat procedures were performed in 13%. The single procedure success was 70% at 1 year (81% for paroxysmal AF, 65% for persistent AF, 29% for long-standing persistent AF) and at 28  13 months follow up was 43% (50%, 41% and 21% respectively), increasing to 59% allowing for subsequent redo procedure with RF ablation (64%, 57%, and 50% respectively). At follow up, LVEF significantly improved to 46  16% (p<0.001), and NYHA reduced to 1.51  0.66 (p<0.001). Conclusion: An initial strategy of cryoablation in patients with AF and LVSD is an effective approach in the treatment of patients with concurrent AF and LVSD. Larger, randomised prospective studies are required to confirm these findings.