‘Single-shot’ pulmonary vein isolation using a novel lotos pulsed field ablation catheter: a pre-clinical evaluation of feasibility, safety, and 30-day efficacy

Figure 1. The study catheter and the pulse parameter used for bipolar PFA. (A1–A3) Multi-electrode catheter gradually deploying into a basic pose (A1), a spindle pose (A2), and a lotos pose (A3). with an 11 Fr shaft. (B) Details of the fully deployed lotos pose (the distal portion is 28 or 31 mm in diameter), shown with 16 electrodes in total. (C and D) Details of a biphasic pulses set. A full cycle consists of a pair of diphasic pulses. PFA, pulsed field ablation.

Figure 2. Fluoroscopic views. (A and B) PFA catheter deployed over-the-wire in LSPVs of swine in the spindle (A) and the lotos (B) pose through a deflectable sheath. Sensing and pacing catheters were placed in the coronary sinus. (C and D) A PFA catheter deployed over-the-wire in RSPVs of swine in the spindle (C) and the lotos (D) pose through a deflectable sheath. Sensing and pacing catheters were placed in the coronary sinus. LSPV, left superior pulmonary vein; PFA, pulsed field ablation; RSPV, right superior pulmonary vein.

Figure 3. Representative electrograms and electroanatomic maps. (A) PV potential disappearing immediately following ablation. (B and C) Changes of pulmonary vein electrograms obtained from the study catheter before and immediately after PFA in the LSPV (B) and RSPV (C), (D and E), Representative voltage maps performed at baseline, immediately after ablation, and 30-day follow-up showing the extent and chronic lesion of isolation in the LSPV and RSPV. LSPV, left superior pulmonary vein; PFA, pulsed field ablation; RSPV, right superior pulmonary vein.

Figure 4. Fluoroscopic views and intracardiac echocardiographic views for safety assessment. (A and B) Baseline, immediately post ablation, and 30-day follow-up venous angiography of the LSPV (A) and RSPV (B) showing no venous stenosis. The dotted line denotes pulmonary veins. (C) A view of the coronary artery before and 8 min after ablation. (D) Intracardiac echocardiographic view of PVs during ablation with spindle pose (D1) and lotos pose (D2), showing no microbubbles. LSPV, left superior pulmonary vein; RSPV, right superior pulmonary vein.

Figure 5. Gross pathology and histopathology of PFA lesions. (A) A PFA lesion in the LSPV with the contiguous broad lesion, shown in gross appearance prior to formalin fixation. The lesion can be identified as white areas of discolouration and is outlined with the dotted line. (B–D) Representative histopathologic images of the chronic cohort of transmural PFA lesion in the LSPV (B and C) and RSPV (D) with structural framework preserved and endocardial sparing, which was conducted 30 days after the procedure. Haemorrhage and myocardium inflammation can be seen. (C) A higher magnification image of the black box outlined in B, demonstrating a sparing of the arteries, veins (arrowhead), and nerves (arrow). (E and F) Representative histopathologic images of target PV in the acute cohort, demonstrating oedema and mild neoendocardium (arrowhead in F). (E) A close-up of the black box area in (F), showing the preserved structural framework with vessels (black arrowhead) and nerves (arrow) retention. The black asterisk represents unaffected epicardial adipose tissue. Masson trichrome staining was used in (B–F). LSPV, left superior pulmonary vein; PFA, pulsed field ablation; RSPV, right superior…