Early recurrence of atrial tachyarrhythmia indicates pulmonary vein reconduction independent of blanking period duration in the RACE-AF trial

Clinical and electrophysiological significance of residual unipolar voltage after performing pulmonary vein isolation in patients with paroxysmal atrial fibrillation

Background

Pulmonary vein isolation (PVI) is the cornerstone strategy for paroxysmal atrial fibrillation (AF). Creating a transmural block line between pulmonary vein (PV) and left atrium (LA) is important for the risk of AF recurrence. Recently, emerging evidence indicates that endocardial unipolar voltage delineates lesions of intramural or epicardial substrate in patients with ventricular tachycardia (VT). However, there are few studies on unipolar voltage evaluation in the atrium. This study describes the clinical and electrophysiological significance of unipolar voltage mapping at the site of PV-LA conjunction after PVI in patients with paroxysmal AF.

Methods

Data from patients presenting for AF ablation from April 2023 to January 2024 at Tottori University Hospital were prospectively included. To assess the electrical isolation, high-resolution voltage mapping was performed comparing groups with and without residual unipolar voltage at the site of cryo-balloon application.

Results

Fifty-seven consecutive patients who underwent cryo-balloon ablation for paroxysmal AF were included in this study. Of these, residual unipolar voltage at the site of PV-LA conjunction after PVI was identified in 22 patients. Patients with residual unipolar voltage after PVI showed significantly thicker left atrial wall thickness and larger epicardial adipose tissue volume compared with patients without residual unipolar voltage after PVI. During follow-up periods, patients with residual unipolar voltage after PVI showed a higher AF recurrence rate than those without unipolar voltage.

Conclusions

Residual unipolar voltage at the site of PV-LA conjunction after PVI may be related to AF recurrence early after the ablation, suggesting the non-transmural block line between PV and LA.

Catheter Ablation in Atrial Fibrillation: Recent Advances

Atrial fibrillation (AF) is the leading cause of arrhythmia-related morbidity and mortality. Recurrent symptoms, hospitalizations, and cost burden to patients have necessitated treatments beyond antiarrhythmic drugs (AADs) for patients with AF. Catheter ablation has proven to be effective over medical therapy alone; however the recurrence rates for atrial tachyarrhythmias post-ablation remain significant, particularly in patients with persistent and long-standing persistent AF. Hence, new techniques for catheter ablation have arisen, such as non-thermal energy sources, novel catheters, electroanatomical mapping, and ablation of additional targets. In this review, we discuss the recent advances in the field of catheter ablation, including newer modalities for the prevention of adverse events and future perspectives.