Left atrial function after atrial fibrillation ablation with pulsed field vs radiofrequency energy: A comparative study

Abstract

Background: The impact of pulmonary vein isolation (PVI) using pulsed field ablation (PFA) on left atrial (LA) function remains incompletely understood.

Objective: To compare the effects of PVI performed with PFA vs radiofrequency ablation (RFA) on LA mechanical function in patients with paroxysmal atrial fibrillation (PAF), using serial echocardiographic strain analysis.

Methods: In this prospective, single-center study, patients undergoing a first-time PVI for PAF with either RFA or PFA were included. All participants underwent transthoracic echocardiography with 2-dimensional speckle tracking analysis at 3 time points: at baseline (immediately before ablation), in the acute phase (immediately after ablation), and in the chronic phase (3 months post-ablation). LA reservoir strain (LASr) and LA contraction strain (LASct) were assessed as primary parameters of LA mechanical function.

Results: A total of 59 patients were analyzed (RFA: 28; PFA: 31). In the PFA group, LASr and LASct decreased significantly in the acute phase (LASr: 26.5 ± 5.8% to 22.9 ± 6.6%, P = .010; LASct: 12.2 ± 3.6% to 8.6 ± 3.1%, P < .001). At 3-month follow-up, LASr had recovered to baseline levels (25.8 ± 7.9%, P = .531), while LASct remained significantly reduced (10.9 ± 4.3%, P = .031). In contrast, no significant changes in LASr or LASct were observed in the RFA group at any time point.

Conclusion: PVI using PFA is associated with acute LA stunning, with persistent impairment in contractile function at 3 months despite recovery of reservoir function. These findings suggest subtle, lasting alterations in atrial mechanics not observed with RFA.

Keywords: Ablation; Atrial fibrillation; Left atrial function; Left atrial strain; Left atrial stunning; Pulmonary vein isolation; Pulsed field energy; Radiofrequency energy.