Treatment of mapped left atrial macroreentrant flutter with electroporation: results and comparison with radiofrequency

Background

Left atrial flutter is a macroreentrant tachyarrhythmia that may occur de novo or, more commonly, as a complication following ablation procedures involving the left atrium. The increasing number of patients undergoing ablation for atrial fibrillation (AF) has led to a growing prevalence of left atrial flutter and a need to optimize its management. Radiofrequency (RF) ablation has traditionally been the standard approach for post-ablation flutters. In recent years, electroporation—also known as pulsed-field ablation (PFA)—has emerged as a promising technology for the treatment of atrial arrhythmias, although available evidence is largely focused on AF treatment with pulmonary vein isolation.

Purpose

To assess the efficacy and safety of electroporation for the treatment of left atrial macroreentrant flutter in terms of clinical arrhythmia recurrence, and to compare its outcomes with those of radiofrequency ablation.

Methods

An ambispective observational study was conducted at our hospital between January 2019 and November 2025. We included 89 patients with left atrial flutter that appeared after or during an AF ablation procedure. RF was employed in 50 patients and PFA in another 39 patients. In all cases, successful activation mapping was performed to confirm a macroreentrant circuit around left atrial anatomical structures using a 3-D navigation system. Atrial flutters driven by scar-dependent reentry were excluded. Survival analysis was performed using the Kaplan-Meier method and differences between survival curves were evaluated with the log-rank test.

Results

Among RF patients, 34 % were female versus 44 % in the PFA group. Mean age was 64 ± 11 years in the RF group and 68 ± 6 years in the PFA group. Mean BMI was 28.5 (RF) and 28.7 (PFA). Mean CHA2DS2-VASc scores were 2.3 (RF) and 2.6 (PFA). Flutter distribution in the RF group was 80% perimitral and 20% roof-dependent, compared with 95% perimitral and 5% roof-dependent in the PFA group. Hypertension was present in 64% of RF patients and 72% of PFA patients; diabetes in 24% and 15.4%, respectively. Structural heart disease was documented in 46% of RF patients (tachycardiomyopathy being the most frequent) versus 28.2% in the PFA cohort.

Arrhythmic recurrence—including atrial fibrillation and left atrial flutter—occurred at 6 months in 31% of RF partients and 12.8% of PFA patients (p< 0.05) and 44% of RF patients and 17.9% of PFA patients, at final follow up (p = 0.008). Survival analysis demonstrated improved left atrial flutter-free survival in the electroporation group, as shown in the accompanying survival curves depicted in picture 1 (p= 0.015).

Conclusion

PFA appears to be a promising strategy for the management of left atrial macroreentrant flutter involving defined anatomical circuits that appears in AF patients. In this study, PFA was associated with significantly improved left atrial flutter–free survival compared with radiofrequency ablation.LAFL survival PFA vs RF