Catheter Ablation -> Atrial Fibrillation & Atrial Flutter: -> Ablation Techniques D-AB24 - Efficacy, Safety, and Potential Advantages of a New Energy Source for Catheter Ablation of Myocardial Tissue (ID 21) Abstract

D-AB24-01 - Pulsed Field Ablation Preserves Atrial Mechanics After Catheter Ablation For Atrial Fibrillation (ID 1455)


Background: Myocardial scar post AF ablation using thermal methods (TH) alters LA mechanics, including contractile and reservoir function. Pulse field ablation (PFA) is a non-thermal modality inducing myocyte death without tissue necrosis and chronic scar.
Objective: To compare the impact of ablation on LA mechanics between PFA and TH using cardiac magnetic resonance (CMR).
Methods: CMR was performed before, acutely (<3h) and 3 months post-ablation in 30 pts with paroxysmal AF undergoing PVI with PFA (N=16, Farapulse®) or TH methods (N=14, 8 RF, 6 cryo). Cine images in 2-chamber and 4-chamber views were analyzed at each time point to quantify LA volume and phasic function, as well as strain in the right and left pulmonary vein areas (RPV and LPV) using a feature tracking algorithm (TrufiStrain, Siemens).
Results: After both TH and PFA, the maximum LA volume tended to decrease between each time point. The LA expansion index and the LA active emptying fraction (reflecting LA compliance and contractility, respectively) showed an acute decline in both groups as compared to baseline. However, both parameters remained altered 3 months after TH ablation, while they tended to recover after PFA (P=0.078 and P=0.045, respectively). The maximum strain on RPV and LPV areas also showed an acute decline in both groups, and a recovery at 3 months only in the PFA group (P=<0.001 and P=0.016 for RPV and LPV).
Conclusion: TH and PFA both induce an impairment of LA mechanics at the acute stage, possibly mediated by myocardial edema. However, as opposed to TH ablation, the compliance of myocardial tissue around PVs recovers 3 months after PFA, which consequently contributes to a preservation of LA phasic function.