Feasibility of reversible electroporation mapping in human atrial flutter.

BACKGROUND

Reversible pulsed field ablation (PFREV) 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 PFREV as a mapping tool in humans.

METHODS

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

RESULTS

In 21 patients, 100 nonpropagated PFREV 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 PFREV 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 PFREV pulses delivered at the outer loop and outside the circuit induced any change. The isthmus was significantly wider when no PFREV effect was observed compared with termination or prolongation (23.2 ± 2.3 mm vs 11.6 ± 2.0 mm; P < .001). When nonpropagated PFREV pulses were delivered at the same site, 85% showed the same type of response, rising to 90% when termination and prolongation were combined.

CONCLUSION

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