Lattice-tip catheter for single-shot pulmonary vein isolation with pulsed field ablation.

Background: A compressible lattice-tip catheter designed for focal ablation using radiofrequency or pulsed-field energies has been recently described. The objective of this study is to describe a new lattice catheter designed for single-shot pulmonary vein isolation (PVI).

Methods: This 8F catheter consists of a compressible lattice tip that is delivered over the wire and is expandable up to 34 mm (SpherePVI™, Affera Inc.). Pulsed field ablation (PFA) was applied from 6 elements using a biphasic waveform of microsecond scale (± 1.3-2.0 kV, 5 s per application). In 12 swine, the superior vena cava (SVC) and right superior pulmonary vein (RSPV) were targeted for isolation. Animals were survived for 12-24 h (n = 6) or 3 weeks (n = 6) for evaluation of short and long-term safety and efficacy parameters. PVI was evaluated immediately after ablation and at the terminal procedure. Ablation-related microbubbles were examined using intracardiac echocardiography and phrenic nerve function by pacing. The tissue was examined by histopathology.

Results: In all 12 animals, PFA resulted in successful acute isolation of the SVC and RSPV using 2.8 ± 1.1 and 3.2 ± 1.2 applications per vein, respectively. After a survival period of 23 ± 5.9 days, all targeted veins remained isolated, and the level of isolation persisted without significant regression or expansion. In one animal, SVC isolation at the level of the right atrial appendage resulted in sinus node arrest. PFA did not affect phrenic nerve function, and it was associated with a few isolated bubbles formation.

Conclusions: In this pre-clinical study, a new expandable lattice catheter designed for single-shot PVI was able to achieve rapid and durable isolation.