Tissue oedema following pulsed field ablation recognized during a concomitant left atrial appendage closure procedure: a case report.

Background: In patients with non-valvular atrial fibrillation (AF), at high stroke risk, and who are ineligible for long-term oral anticoagulation, the left atrial appendage closure (LAAC) could be an alternative to anticoagulation. Pulsed field ablation (PFA) is a new non-thermal method for cardiac ablation modality based on high-voltage electrical energy for irreversible electroporation. We first report a case of a concomitant PFA pulmonary vein isolation (PVI) and LAAC.

Case summary: A 74-year-old female patient was referred to our department for PVI for persistent AF (CHA₂DS₂-VASc score 5). A concomitant percutaneous LAAC was proposed because of a history of previous cerebellar transient ischaemic attack despite continuous oral anticoagulation therapy. Pulmonary vein isolation was achieved with a pentaspline PFA catheter, and LAAC was performed with a WATCHMAN FLX™ device (Boston Scientific, Plymouth, MN, USA). After PVI, a swelling of the left atrial ridge was observed, yet a 27 mm LAAC device was successfully implanted. The follow-up transesophageal echo (TEE) after 6 weeks showed complete resolution of the oedema, no device-related thrombus, but a slight proximal tilting of the LAAC device without leakage could be observed. The 6-month follow-up demonstrated a stable sinus rhythm, no stroke, or bleeding events were recorded.

Discussion: In this case of synchronous PFA-PVI procedure in AF and WATCHMAN FLX™ device implantation, the electroporation created an acute oedema at the ridge level which at the TEE follow-up after 6 weeks was resolved. This resulted in a slightly tilted WATCHMAN device position which was nevertheless stable and showed no leakage.