Balloon-Shaped Pulsed Field Ablation for Pulmonary Vein Isolation and Atrial Lesions

The cryoballoon catheter is a gold-standard single-shot device for pulmonary vein isolation (PVI). Pulsed-field ablation (PFA) is a tissue-selective, nonthermal cardiac ablation modality. We assessed the preclinical safety and durability of a novel conformal, balloon-shaped, single-shot PFA catheter for PVI and circular atrial lesions.

A 13 Fr balloon-shaped PFA catheter (PFBalloon^TM, 20 electrodes, 24 mm diameter, EnChannel Medical) was applied using a biphasic waveform of microsecond scale (± 750 V, 4.9 s per application). In 10 swine, superior vena cava (SVC), left superior PV (LSPV), right superior PV (RSPV) and right atrial appendage (RAA) were targeted for isolation. Localization of PFBalloon was evaluated by fluoroscopy and intracardiac echocardiography (ICE). PFA was delivered in a novel tailored configuration (small ring, large ring, or global pulse) to minimize diaphragm stimulation and optimize pulse efficiency. Five swine were assessed at 30 days post-procedure for lesion durability, gross pathology, and histologic examination, while the remaining five swine were evaluated at 90 days to assess longer term outcomes.

In all 10 swine, PFA resulted in 100% successful acute isolation of the SVC, RSPV, and LSPV using 4.2 ± 0.6, 5.0 ± 1.1, and 4.4 ± 1.8 applications per vein, respectively, and acute isolation of RAA in 9/10 swine using 5.3 ± 2.0 applications. At 30 days post-procedure, 14 out of 20 targeted sites (70.0%) remained isolated in five pigs. At 90 days, 19 out of 20 sites (95.0%) remained isolated in the remaining five pigs. The overall pulse configurations were 9.0% small ring, 25.4% large ring, and 65.6% global. PFA did not affect phrenic nerve function, with very few microbubbles recorded on ICE. No major complications were observed.

In this preclinical study, a novel conformal, balloon-shaped catheter designed for single-shot PVI can create durable isolation without complications.