Feasibility and acute outcomes of cavotricuspid isthmus ablation using the circular-array pulsed field system.

BACKGROUND

Pulsed-field ablation (PFA) is a novel nonthermal energy source that has shown favorable procedural safety and efficiency in pulmonary vein isolation. However, its utility in cavotricuspid isthmus (CTI) ablation, particularly with circular-array catheters, remains uncertain.

OBJECTIVES

To evaluate the feasibility, acute efficacy, procedural characteristics, and complication profile of CTI ablation using a circular-array PFA system.

METHODS

This retrospective study included 55 consecutive patients who underwent CTI ablation with a circular PFA catheter. Procedural parameters—including comparisons with radiofrequency (RF) ablation—PQ intervals, voltage mapping, and adverse events were analyzed.

RESULTS

Bidirectional CTI block was achieved in all patients. The median number of applications to achieve block was three, with a total of eight applications per case. The median time to block and total ablation time were significantly shorter than those observed with RF ablation (79 sec vs. 324 sec; p < 0.001, 291 sec vs. 432 sec; p = 0.003). High-density mapping demonstrated extensive low-voltage lesions, with a median minimum width of 18 mm (IQR: 12–23) and maximum width of 30 mm (IQR: 23–35). Coronary spasm occurred in three patients (5.5%) but resolved with vasodilators.

CONCLUSIONS

CTI ablation performed in conjunction with atrial fibrillation ablation using a circular-array PFA system appears to be a feasible and time-efficient approach. In the absence of prophylactic vasodilator administration, coronary spasm was observed even with the circular-array PFA system, underscoring the need for further investigation under vasodilator-supported conditions. Circular-array PFA created extensive low-voltage lesions with short procedural time and achieved 100% acute CTI block. Procedural efficiency was unaffected by right atrial volume or CTI length, while coronary spasm occasionally occurred in the absence of vasodilators, warranting further evaluation under vasodilator pretreatment.