High power short duration (HPSD) ablation may improve pulmonary vein isolation (PVI) durability and shorten radiofrequency ablation (RFA) time. Measurement of local impedance (LI) drop on ablation using the DIRECTSENSE software module, an advanced feature of RHYTHMIA mapping system has shown to assess acute lesion durability but has not been clinically studied with HPSD.
This is the first study to assess feasibility of LI measurements at each RFA for acute lesion durability using HPSD.
Fifteen de-identified patients underwent PVI at University of Iowa Hospitals. Mapping was performed using RHYTHMIA® (BSc) using the small basket catheter (Orion®; BSc). An Irrigated, 4.5mm tip, IntellaNAV MiFi OI (BSc) ablation catheter was used. HPSD (50W, 5-10 second duration) ablation lesions in the endocardial left atrium were analyzed. Baseline LI, baseline generator impedance (GI), LI drop and GI drop, power and duration were recorded for analysis. Acute lesion durability was assessed by high density validation mapping post ablation.
A total of 1,207 lesions were analyzed. No complications were noted. Majority of the patients were male (67%), had persistent AF (75%) and were undergoing Re-do ablations (73%). The mean baseline LI and GI for each lesion were 108Ω and 100 Ω, respectively. The mean LI drop for the durable lesions was 21Ω (19%) vs 10Ω (10%) for those without. The mean GI drop for the durable lesions was 21Ω (21%) vs 18Ω (18%) for those without. Baseline LI and LI drop had a higher linear correlation for acutely durable lesions (R2 = 0.38 vs 0.10).
Our study shows feasibility of utilizing LI drop in PVI utilizing HPSD lesions.
© 2021 Published by Elsevier Inc.