Pranav Bhagirath

92 Chapter 5 ABSTRACT Background: Patient selection for atrial fibrillation (AF) ablation remains challenging as the currently used parameters, such as left atrial volume, are often poorly correlated with post-procedural AF recurrence. This is especially the case in patients undergoing repeat ablation. Recent investigations have reported left atrial sphericity (LASP) as an independent and strong predictor of success for index AF ablation procedures. Objective: This study investigated the utility of LASP in predicting AF recurrence following a repeat ablation. Methods: Patients undergoing repeat ablation for AF were included. Contrast enhanced computed tomography, acquired prior to and following the index ablation procedure, was used for creating a left atrial segmentation. LASP was computed using custom- made software. Results: 25 patients (61 ± 8.4 years, 80% male) with paroxysmal (40%) and persistent (60%) AF were included. Fourteen patients (56%) had AF recurrence after the repeat procedure. No relation was observed between recurrence and the nature (p=0.62) or duration of AF (p=0.51). There was no significant correlation between LA volumetric changes and AF recurrence (p=0.17). Only the change in LASPwas significantly relatedwith AF recurrence (p<0.001). All patients with a positive change in LASP were free from AF recurrence during the follow-up (664 ± 245 days). Conclusion: Changes in LASP following the index ablation correlate with outcome of repeat catheter ablation procedures. Positive changes in the LASP (reverse remodeling) are strongly related to a higher success rate of the repeat procedure. Patient selection for repeat ablation could be improved by including geometrical remodeling as a stratification factor.