Lesion effects in terms of local impedance variations after pulsed-field ablation during pulmonary vein isolation: a case report

Abstract

Abstract Background To date, no information is available on highly localized impedance (LI) measurements during the ablation of pulmonary veins (PVs) via a new form of energy such as electroporation by means of pulsed-field ablation (PFA). Case summary A 55-year-old man with a history of paroxysmal atrial fibrillation was admitted to our hospital for PV isolation (PVI). The procedure was performed with the new multi-electrode PFA catheter (FARAWAVE™). Before energy delivery, a high-density map of the left atrium was constructed with the Rhythmia™ system, while the IntellaNAV Mifi™ OI catheter was used to assess the baseline LI values of the four PVs. A manual tag was used to record the exact position where the IntellaNAV™ catheter measured the LI values for each segment of the vein before and after PVI. The LI values displayed a significant variation after PFA delivery (124.3 ± 5 Ω for baseline LI vs. 96.8 ± 6 Ω after PFA, P < 0.0001) with a mean absolute LI variation of 27.5 ± 7Ω and a mean percentage LI variation of 25.8 ± 8%. The differences between the average LI values pre- and post-PFA were 28.0 ± 5, 26.5 ± 9, 26.8 ± 3, and 28.8 ± 10 Ω for the superior, anterior, posterior, and inferior portions of the PV. Discussion This is the first instance of the acute characterization, in terms of LI drop, of antral lesions created by a new PFA system. Local impedance variations at ablation sites seem to be larger than those recorded at successful ablation spots obtained by means of thermal energy sources.