Feasibility of reversible electroporation mapping in human atrial flutter

Abstract

Background: Reversible pulsed field ablation (PF_REV) can temporarily block conduction and may emerge as a novel clinical mapping tool to accurately identify critical isthmuses before permanent lesions are created.

Objective: We aimed to assess the feasibility and performance of PF_REV as a mapping tool in humans.

Methods: PF_REV pulses were delivered with a 9-mm lattice-tip ablation catheter in 24 atrial flutters, targeting sites in and outside the circuit. Only nonpropagated PF_REV pulses without change in activation sequence were analyzed.

Results: In 21 patients, 100 nonpropagated PF_REV pulses were delivered in 24 tachycardias; 74 (74%) pulses were delivered within the circuit (54 at the isthmus and 20 at outer loop sites), and 26 (26%) pulses were delivered outside the circuit. Three responses were observed: termination, tachycardia cycle length (TCL) prolongation, and no effect. Of the PF_REV pulses delivered at the isthmus, 9 (16.7%) led to termination, 10 (18.5%) led to TCL prolongation, and the remaining 35 (64.8%) had no effect. None of the PF_REV pulses delivered at the outer loop and outside the circuit induced any change. The isthmus was significantly wider when no PF_REV effect was observed compared with termination or prolongation (23.2 ± 2.3 mm vs 11.6 ± 2.0 mm; P < .001). When nonpropagated PF_REV pulses were delivered at the same site, 85% showed the same type of response, rising to 90% when termination and prolongation were combined.

Conclusion: PF_REV mapping of reentrant atrial tachycardia is feasible, with termination and TCL prolongation reproducibly identifying the critical isthmus with 100% specificity. Sensitivity of PF_REV mapping is influenced by the isthmus electroanatomic characteristics.

Keywords: Atrial flutter; Lattice-tip ablation catheter; Mapping; Pulsed field ablation; Reversible electroporation.